For as long as I have been writing about cars, Acura, the move-up division of Honda, has been struggling to create an identity for itself.

Part of the problem is its positioning. Unlike Lexus and Infiniti, Acura was never conceived as a full-bore attack on the German luxury carmakers, but rather a step up for Honda buyers. So while Acura markets cars in small, medium, and large sizes, just like the Germans, they are several notches lower in price and prestige.

Another part of the problem is perceived exclusivity. Two-thirds of Acura’s current passenger car lineup is based on the Honda Accord sold in Europe, a heritage that isn’t going to appeal to status seekers. Over the years, Acura’s styling has been appropriately conservative without being distinctive. And its nomenclature is forgettable, with the model range designations going mysteriously from TSX to TL to RL.

So while Acura is three years older than Lexus or Infiniti, it hasn’t been able to use those extra years to establish a higher profile. Even difficult economic conditions haven’t helped, despite Acura’s generally lower price points and superior gas mileage. Its sales have fallen 34% this year, more than its luxury competitors.

A car that could raise Acura’s recognition factor is the TL, the mid-size in the lineup. Powered by a 305-horsepower V-6 and available with a six-speed manual transmission, it has been praised by enthusiasts for its smooth shifting and zesty performance.

I was less impressed. When navigating through a six-speed gearbox, it is helpful to have an indicator of the instrument panel to tell you what gear you are in; Audis do but this Acura did not. The TL also seemed to reward higher-rev shift points than I am accustomed to using. Down in the lower revs, I found myself downshifting frequently on hills despite the reputedly torquey characteristics of the engine

What I did like was the TL’s design: aggressive but not so much as to scare small children. The paint job, in a deep radiant black, sets a standard for this class of car. The interior was as handsome as Honda products ever get, and the instruments were characteristically clear in function and easy to use.

Honda likes to position the TL as a rival for the BMW five-series. With an as-tested price of $44,195, that would make the Acura a bargain. I’d rather think of it as a range-topping Accord with a special appearance package. And I would very much like to test one with an automatic transmission that does the shifting for you to fully appreciate this impressive machine.

In my experience, all proper German cars come in two colors: silver and black. There is a reason for this, as there is in all things German. These colors denote a seriousness of purpose, obliviousness to fashion, and a sticker price that takes your breath away.

But when I asked Mercedes to review an example of its new E-class line, the car I received was not silver or black but red — “Mars Red” in official Mercedes-ese.

I was confused. Was Mercedes trying to send me a message that times are changing at the world’s oldest automaker? Or had all the silver and black cars been snapped up by my competitors at Motor Trend, Edmunds, and Jalopnik?

Let’s review the evidence.

The E-class coupe replaces the two-door in the Mercedes lineup formerly known as the CLK and becomes part of the larger, more expensive E-class line. That’s one change.

Physically, the car harks back to its CLK roots but psychically, its aura has changed. The dimensions of the E-coupe platform are identical to the smaller, less-expensive C-class yet the car has the fittings, feel, and solidity of a larger E-class sedan. You could say the E-coupe merges C-class specifications with E-class ambiance. That’s another change.

My test car, which was equipped with a 5.5-liter, 382 hp V8, bristled with as much muscle as I wanted to handle, and the interior was top shelf. On the road, the coupe displayed the ride and dynamics of an E-class, combined with the handling and fuel economy of a C-class. In Mercedes tradition, comfort and predictability took precedence over razor-sharp reactions.

Fuel economy was impressive. Under the EPA driving cycle, the E-coupe is expected to deliver between 19 mpg and 27 mpg on the highway, and I consistently hit in the high end of the range.

That was good for the environment but not for my bank balance, since the premium grades of gasoline that Mercedes recommends run 10 cents to 20 cents more a gallon than regular.

The final piece of evidence showing that the E-coupe represents new thinking was the price. Mercedes prices its coupes aggressively but this was still a surprise. The base sticker price of the smallish E-coupe is $54,650 , only $1,650 less than the larger E-class sedan.

My car was equipped with the premium package (navi system, upgraded audio, rear view camera), Distronic Plus package (smart cruise control, parking guidance), appearance package (wheels, seats) and the wood/leather steering wheel package.

All together, that pushed up the total retail price to $67,125. That’s a handsome price for a handsome car in these economically distressed times.

By way of comparison, for the same money, you could move up two classes in size and pick up a used S-class sedan — a proper silver or black one.

If General Motors is able to convince the world that it can build cars that people actually want to buy, it has to start with the new models it launches over the next several months. Taxpayers, customers, and journalists all will be watching carefully.

In a sense, the attention is unfair. These are Rick Wagoner cars, planned and developed three years ago under the former CEO. Fritz Henderson cars won’t be coming along until 2012.

Still, GM has been arguing for some time that it builds world-class automobiles; all that’s missing now is its ability to convince convincing customers about the validity of that claim.

The 2010 Buick LaCrosse perfectly illustrates the problem. Stick a Lexus or an Acura label on it, and you would have a competitive car, one you would take on a second honeymoon to Napa Valley.

Let people know it is a Buick, however, and they expect to see it parked in front of Applebee’s for the early-bird special.

Badging aside, the LaCrosse ranks as my favorite GM sedan. Driving around the Detroit area, I was never disappointed.

What did I like about it?

First of all, the price. Even with 18-inch chrome wheels and other options totaling $1,850, the LaCrosse carried a sticker price of just $31,495. That’s a really good value for an entry-luxe mid-size sedan.

Second is the exterior design. With its high belt line, fast sloping rear end, and tasteful chrome accents, the LaCrosse is international in character and American in spirit. I even don’t hate the porthole simulations on the hood.

Third is the interior, bright and classy without being garish. You can argue about the unnecessary stitching, plastic wood, and overly busy instrument stack. But overall I felt comfortable and pampered, without any pandering.

Over the road, the Buick behaves like a large front-wheel sedan for aging baby boomers. Performance from the 3.0 liter V-6 is adequate — 60 mph arrives in eight seconds. For those who want more power, a 3.6 liter V-6 is available. The cabin is well insulated to screen out any unwanted noises. Fuel economy is an acceptable 17 mpg city/26 mpg highway.

For Buick to succeed and GM to prosper, the brand has to attract buyers who bring the average owner age down by a decade from the high 60s. Some better advertising and smarter marketing should do the trick.

With LaCrosse, Buick has the hardware; all it needs now is the image to go with it.

Poison for many manufacturers, the 2009 model year has been an elixir for Subaru. It is one of only two brands (the other is Kia) to show a sales increase this year. In an industry that is off 27.9% for the first eight months, Subaru is up 11.2% and is closing in on Mazda for 11th place in overall U.S. market sales.

Subaru manages all this with just three car lines and one truck (Mazda currently has a total of eight) and in this case focus pays off. The pre-production Legacy sedan I drove recently (Legacies are the top of the Subaru line) looked and felt like a much more expensive car. Base price is $19,995, but even at $24,995 (plus a $695 delivery charge) for my test car, I believe it is a remarkable value.

Subarus used to have a quirky streak, but the all-new mid-size Legacy looks muscular and mainstream without being boring. Inside I felt unusually well looked-after. The cabin was upscale without being fussy and the level of workmanship surprisingly high. All the touch points and instruments were sturdy and functional and unlikely to lose their appeal after years of use.

That’s an important consideration for Subarus. I have a friend who happily putts around in a Legacy wagon that dates from the first Clinton administration. It isn’t particularly stylish, but it is reliable, and he sees no need to replace it.

Like all Subarus, the Legacy comes with standard all-wheel drive and a new CVT transmission that boosts the EPA mileage rating to 23 mpg city/31 highway. That is so good that it beats the rating for the manual gearbox.

Oddly, Subaru provides paddle shifters for gear changes on the CVT, even though the transmission has infinite variability with no fixed gear ratios. I found myself downshifting on hills in order to maintain speed but I needn’t have bothered.

It is a little difficult for me to identify the factors behind Subaru’s success. It has been successfully upgrading its product line, but all manufacturers try to do that. Unlike Kia, Subaru has been building from a solid position to a stronger one, so there’s nothing dramatic there, either. Nor has there been any standout model or eye-catching ad campaign to create buzz.

So attribute Subaru’s success to the company’s unspectacular but highly competent management team, their U.S. headquarters in a Philadelphia suburb well away from the automotive mainstream — and a buying public that, in difficult economic times, knows where to find a good value.

Think of Subaru’s success in 2009 as a victory for common sense.

The minute I climbed into the driver’s seat, I knew: General Motors is getting its mojo back.

It may sound strange, but for a long time GM has felt lost in the product development wilderness. Some of its cars were simply duds. Others, even the ones deemed more successful, like the Chevy Malibu and Cadillac CTS, felt overly thought out and excessively mannered.

GM has been in the car business for 101 years. Why did it seem to have to relearn what it is doing, time and time again?

My Equinox experience was especially notable given my opposite reaction to a similar vehicle, the Cadillac SRX, a few weeks earlier. The SRX felt like it was developed by following the results of focus groups that weren’t coordinated with each other. The result was a mashup of features and functions that didn’t match up.

Not so in the Equinox. Everything is of a piece and seems to fit this midsize crossover. Its controls are all in the right place and function smartly the way they should, and none of the instruments or trim was fighting for my attention.

Likewise, the exterior design was well-resolved and identifiably Chevy, without slopping into the self-referential or overly mannered.

Unfortunately, some of the good feeling abated once I got underway. Although the Equinox came equipped with the optional 264-horsepower V6, it labored going up hills, refusing to shift down until the very last moment.

Would that be a deal-breaker? It depends on the terrain where I expected to drive.

The Equinox competes in a cutthroat segment against Honda’s CR-V and Toyota’s RAV-4. It is up to a foot longer than the competition and weighs several hundred pounds more but carries nine cubic feet less.

As the newest car in the segment, the Equinox is also the priciest. Loaded up with more than $5,000 worth of optional equipment, my test car carried a sticker price of $33,235.

It isn’t the best, and it isn’t cheap, but I consider Equinox competitive in this segment, and it has been a long time since I’ve been able to say that about a non-truck GM product.

The success of the Equinox bodes well for future Chevys due in the next year or so, like the Cruze, Spark, and Volt.

Getting its mojo back would be good for GM and good for the rest of the auto industry. GM should devoutly hope that Equinox is not just one of a kind.

Let’s get it out of the way right at the top: The new convertible version of Aston’s V-12 powered 2+2 grand tourer (with automatic transmission) carries a sticker price of $285,990.

That’s crazy, right, as we struggle to emerge from the worst economic downturn since the Great Depression?

But let’s consider this: The DBS Volante is the most drop-dead gorgeous, most satisfying car I can ever remember driving.

More refined and sophisticated in appearance than a typical Italian supercar, yet more expressive than a Porsche or a Jaguar, the Aston is stunning to look at. Every detail, from the four mesh inserts in the hood and the flared headlamp openings to the carbon fiber door handles is executed with an extra helping of panache that elevates it from the merely attractive to the alluring.

My test car glowed in a hue that Aston endearingly describes as Hardly Green that was both unique and eye-catching, and worked nicely with the brown leather surface coverings.

The view from behind the wheel is no less stunning. The winged Aston emblem dominates the steering wheel, the instruments are finely calibrated, and the Bang and Olufsen audio provides superb fidelity.

Fire up the six-liter engine by inserting the ignition device in its slot, and the Aston barks to life. Onlookers snap to attention. Select a gear by punching one of the traditional Aston dashboard buttons and you are off.

Power arrives smoothly and you can feel the six-speed transmission shifting smoothly up and down through the gears, proceeding so smartly that manual gear changes would be an insult to the software.

My agreement with Aston prohibited me from performance tests like 0-60 acceleration, so I can only report the company’s claim that 62 miles per hour can be reached in 4.3 seconds and top speed is 191 miles per hour.

As for flaws, I can identify but two: The carbon fiber chin spoiler is so close to the ground that it inhibits travel over rough surfaces, and the trunk is too tight to accept a bag of golf clubs.

But practicality isn’t the point here. Like a fine watch, the DBS Volante represents an ambitious expression of the mechanical arts.

For those who can afford to indulge such pleasures, and who can accommodate a Volante in their fleet of automobiles, it is an entirely worthy addition.

I would consider it a modern-day classic, for which paying the unreal sticker price is merely part of the pleasure of ownership.

Jaguar is at another turning point in its storied and eventful history. It is operating under a new owner, Tata Motors of India, while it launches models developed under its old owner, Ford.

The global economic downturn hasn’t been kind to Jaguar but it hasn’t impacted its product cycle either. Coming soon to dealers is the XF-R, a supercharged version of the midsize sedan, and an all-new XJ — the Jaguar flagship.

The model under review, the XK-R, has also been reworked for 2010. The spiritual, if not functional, successor to the historic XK-E, this two-plus-two features a new supercharged V-8 engine that puts out 510 horsepower and hustles the coupe to 60 miles per hour in a reported 4.6 seconds — should you have an opportunity to exercise it in that fashion.

The interior has been made over as well, with instruments and a silver rotary gear selector adapted from the XF. The gear selector has been criticized by some as too gimmicky, but I found it more ergonomically suitable than the dashboard mounted switches that the German luxury car makers have been experimenting with.

Historically, Jaguars have been among the most esthetically-pleasing (if not mechanically accomplished) cars on the road, and, for me, the XK-R is one of the Jag’s greatest hits. There isn’t a false note or awkward line on it, and the overall shape, with the long hood and suavely tapered rear, is enormously appealing.

The car drove the way it looks, smoothly and effortlessly. The level of intensity it required entirely depended on the demands made by the driver. All of its power and dynamic capability waited unobtrusively until it was requested.

The price for this élan is not insignificant. With 20” wheels and special paint, the total suggested retail price on my car came to $102,000. For those whose lives can accommodate what is basically a two-seat hatchback, and have the means at their disposal to afford it, the XK-R is a worthy investment.

Jags are still made in the U.K. and still source most of their parts from the British homeland. So those who turn up their noses at the idea of this fine old marque under Indian ownership have no substantive issues on which to base their bias.

Yet, as Tata, which bought Jaguar in 2008, enters Western markets for the first time, it is faced with a significant challenge. It has inherited a piece of automobile history that has been buffed to a high sheen by its previous owner. It remains to be seen what Tata make of the automotive heritage with which it has been entrusted.

For the first time since the aero-shaped original made its debut in 1985, the Ford Taurus has become big news again.

There are three important reasons why:

1.    This is the first new Ford to reflect the input of CEO Alan Mulally.

2.    This is the first new Ford to arrive since the company forsook government assistance and still dodged bankruptcy — unlike General Motors and Chrysler.

3.     The 2010 Taurus represents the latest American entry into the full-size car segment where Detroit needs to stake a new claim if it is to regain credibility in the marketplace.

From an engineering and design standpoint, the Taurus is a success. It is stylish, contemporary, and functional. But it will face fierce competition because it is relatively large, relatively heavy, and relatively expensive.

The original Taurus was a middleweight that contended for the most popular car crown with Accord and Camry, and in some years sold around 400,000 units.

The 2010 Taurus is a heavyweight (more than 4,000 pounds), which goes against other full-size vehicles such as the Toyota Avalon and Chrysler 300. Ford (F) would like to sell just 80,000 a year.

The new Taurus has more bling than the old one, including extraneous vents in the front fenders and a superfluous character line on the flanks. The new lower profile is a plus and the Taurus has a raked stance that makes it look faster when it is parked.

The interior is first-class all the way: high-grade materials, smart layout, highly visible controls. Following Mulally’s dictate that all Fords have similar driver interfaces, the Taurus also comes with Formula One-style, steering-wheel mounted gear shift flippers, perhaps not needed for a car mostly driven by patrons of the Early Bird dinner. Electronic navigation features, like blind-spot detection in the rearview mirrors, are extremely helpful and should be standard equipment for everybody.

On the road, the Taurus drives like a big car. The chassis feels like it is made out of rebar and the chunky seats wouldn’t be out of place in a men’s club. My test car suffered from a ticklish accelerator pedal but otherwise purred on the highway, without ever suggesting it was interested in anything athletic. Its trusty 3.6L Duratec V-6 delivered 22 miles per gallon in mostly highway driving. Those craving excitement are advised to seek out the SHO, with its 3.5L turbocharged V-6.

With delivery charges, my ingot silver metallic test car carried a base price of $31,170 that rose to $38,080 with a couple of options. The 2010 Taurus isn’t going to ignite the world the way its ancestor did, but it should draw some shoppers back to Ford showrooms. If they postpone their visit until next year, they will see some more eagerly-awaited new Fords, like the Focus and Fiesta.

For a mid-summer run on the Berkshire back roads to a Saturday evening performance by the Boston Symphony at Tanglewood, it would be difficult to beat my TTS roadster. The top was down, the stereo was pumping out classical tunes from Sirius satellite radio, and the brilliant red TTS was the best looking car on the road — though not so good looking as to attract the attention of any Massachusetts state police, who were anyway otherwise engaged directing concert-going traffic.

The “S” designation identifies the sport version of the well-known TT roadster. An $8,200 bump in the base price gets you a pumped-up version of Audi’s 2.0 liter turbocharged engine that puts out 265 horsepower (vs. 200 hp in the TT) as well as a host of appearance features like 19-inch 7 twin-spoke wheels. Audi doesn’t make any ugly cars, and the front end, with a body-colored bar bisecting the iconic horseshoe grille, is the brand’s best looking.

The Quattro all-wheel drive system keeps the TTS planted through the tightest curves, and acceleration at higher revs is impressive. There is one important performance exception, though: The turbo is slow to spool up at low engine turns, creating sponginess underfoot and uncertainty before you attain cruising speed. I eventually discovered that a slow, even throttle advancement produced better results than an impulsive stab. But I missed the feeling of power under pedal I remember from a Porsche Boxster.

With its stubby but refined bubble shape, the TT is a modern design classic whose looks are only improved in this latest version. And thank goodness Audi didn’t follow BMW by adding a power retractable hardtop. The TTS’s convertible fabric roof is as tight as it needs to be and raises and lowers in seconds, never impinging, needless to say, on the surprisingly commodious trunk.

Owning a TT is a very special experience these days. Only 951 new ones changed hands during the first half of the year, only a fraction of those were roadsters, and only a fraction of THOSE were ”S” roadsters. The $55,075 sticker price for my test car gives you one big clue why. Still, there is nothing else quite like it on the road, and I can begin to justify the purchase to myself if I think about it as an investment, like a mechanical Swiss watch, to be handed down to future generations.

If that proves inadequate, I can always plan more trips to Tanglewood.

It is rare that the appearance of a car isn’t diminished by the addition of a retractable hardtop roof. The storage requirements for all that metal and machinery usually dictate a wider and higher rear end than is esthetically desirable. Check out the Chrysler Sebring convertible for an especially egregious example.

Not so with the newly grown-up Z4, which may be the best-looking BMW of all. Its tightly-tailored butt is balanced by a long, long front end, with attractive accent lines on the flanks. The effect is to create a modern car with classic proportions. Think pre-war Mille Miglia.

The Z4 interior closes the deal. It combines intelligent functionality and helpful info-graphics with a stylish touch not seen in earlier models, which to my eye were obsessively Spartan.

The Z4’s good looks are combined with stylish road matters. My test car was powered by a 3.0 liter, 255-horsepower inline-six. (The 300 horsepower twin-turbo six is also available). With the automatic transmission, the 3.0 is reported to get the car to 60 miles per hour in six seconds flat. The steering is typically precise, and the suspension produces a nice blend between a sporty ride and one that is comfortable. Mileage is a none-to-shabby 19 miles per gallon city/29 mpg highway.

All of this excellence comes at a price, both financially and functionally. While the base price of the Z4 is $45,750, my test model with the smaller engine came in at nearly $60,000, which included $500 for heated front seats and $350 for a high-definition radio.

That helps explain why Z4 sales are less than robust: BMW sold 361 in July. By comparison, it sold 427 X6s and 807 7 series.

Then there is the matter of trunk space. You’d never get a bag of golf clubs into the trunk of a Z4, but with the top down, you’d have a hard time even squeezing in a shaving kit. That puts a limit on the places you’ll go.

Sadly, the combination of price and space limits the appeal of the Z4 to a very small number of owners. Too bad. A car this good deserves a wider audience. Perhaps this leaves an opening for BMW to bring back the old cloth topped, four-cylinder Z3, with a smaller price tag and more room in the rear.