Cadillac's version of the Corvette, now in its second year of production, continues to be one of my favorites. Called the XLR, this new Caddy is the first true sports car from General Motors' luxury brand.

Its style, grace and power make it a great halo car for the franchise, a vehicle that sort of sums up all the good things that have been happening at Cadillac during the past five years.

Developed from the Evoq concept car Cadillac unveiled at the 1999 Detroit auto show, the XLR is Cadillac's first two-seat roadster since the demise of the Allante, which faded away quietly in the early '90s after a brief and mostly unsuccessful run.

Although the Allante was a sporty car, it really wasn't a sports car in the vein of a Corvette or Mercedes SL, and that's exactly what you get with the XLR.

The XLR got a head start on the new sixth-generation of the Corvette, which arrived in dealerships this past fall. The Cadillac went on sale in summer 2003 as an '04 model. Built on the same chassis as the C6, and in the same plant, in Bowling Green, Ky., the XLR's close relationship to the Corvette should be enough to ensure its success.

As GM designers and engineers went to their drawing boards and computers to come up with the next generation of the 'Vette, they also had this new Cadillac in mind, so it wasn't just an afterthought, a minor reskinning of the 'Vette to create a more luxurious sports car.

Among its high points are its dramatic styling, carrying Caddy's art-and-science design theme that made its debut in 2002 on the new CTS midsize sedan. That theme now has been carried over into a variety of outstanding new Cadillac models that have come to market since 2003, including this year's all-new STS full-size sedan.

Another high point of the XLR is its revised Northstar powertrain, a new version of the 4.6-liter V-8 engine that powers most other Cadillacs.

But therein lies the only potential negative in the XLR package. With a pricetag beginning at just over $76,000 - about $30,000 more than the base 'Vette - the XLR takes a back seat to the Corvette in performance.

The new Corvette comes with a new 6.0-liter V-8 rated at 400 horsepower, compared with 320 horsepower for the XLR's V-8. And the Corvette Z06 model unveiled at the Detroit auto show in January will come with a 500-horsepower V-8.

If raw engine power is all you're concerned about, then the Corvette might be the better choice, and it's even less-expensive.

Or you might wait a few months and choose the newest version of the Cadillac roadster - the XLR-V - which was introduced this past week at the New York auto show.

The XLR-V, to arrive as a 2006 model, will come with a new 440-horsepower Northstar SC V-8 and all-new Hydra-Matic 6L80 six-speed transmission. Oh, yeah - it's supercharged, too.

GM says it will achieve zero to 60 mph in under five seconds. It also comes with 19-inch wheels and a leather-wrapped interior.

No prices have been announced for that one yet, but I expect it to be somewhere in the upper $80,000s. That will make it about the same price as the Mercedes SL500, with 302 horsepower, but considerably cheaper than the 493-horsepower SL600, with its $128,000 pricetag.

Let me say, though, that the XLR as it is, with the 320-horsepower engine and $76,000 pricetag, seems to be a better value than the SL500 at $14,000 more (with less power).

With Mercedes' recent quality problems, the XLR has even another edge besides price and power; Cadillac products today rank at or near the top in quality and reliability. That 4.6-liter engine is no slouch, either. The car goes from zero to 60 mph in just 5.8 seconds.

As for comparisons with the Corvette, the XLR emphasizes luxury more than the 'Vette does, which is in keeping with the luxury mission of the Cadillac brand. In that respect, it is positioned to compete against cars from Mercedes, Jaguar and BMW more than against its own GM cousin. This car goes after a different sort of customer than the Corvette.

Even with its high-performance drivetrain and sporty suspension, the XLR rides more like a Cadillac than a Corvette but still handles well on twists and turns. The car certainly turns heads, in part because most people have never seen a Cadillac this beautiful.

Technology abounds in the XLR , including such items as the fully retractable power hard top, adaptive cruise control, magnetic ride control, computerized stability control, Magnasteer power steering, GPS satellite-based navigation, keyless access with push-button start, heated and cooled seats, and the OnStar communications system.

Keyless access is one of the most-convenient features on the XLR . As the person with the key fob approaches the car, it automatically unlocks and readies itself for engine starting. The driver can keep the key fob/remote control in his or her pocket, push the start button on the dash and watch as the car will start and drive without having to insert a key into the ignition switch.

The XLR's retractable hard top allows for a quieter with the top up than you would get with a canvas-top convertible. It's also more secure and better-looking than a soft-top roadster. Car Top Systems of Germany, responsible for the designs of many top-rated convertibles, developed the XLR top, GM said. By pushing and holding one button, the XLR goes from coupe to open roadster in less than 30 seconds.

The top is installed as a complete module and is made of aluminum and magnesium, with composite exterior panels, a heated glass backlight and glass rear-quarter windows, the company said.

Inside, the car is pure luxury, but that's not overdone. Included are touches such as eucalyptus wood and aluminum accents. The gauges were designed in conjunction with Italian luxury brand Bvlgari.

For now, the car comes only with a five-speed automatic transmission - another place where it differs from the Corvette, which comes with either an automatic or a six-speed manual gearbox..

Having only an automatic in the XLR is another way of likening the car more to the SL500, Jaguar XK8 or Lexus SC 430 than to a Corvette, which is geared more toward the enthusiast crowd. The XLR , SL500 and SC 430 all emphasize luxury over performance and are designed to appeal to a slightly older, more refined, wealthier customer.

Like the Corvette, of course (since it's much the same car underneath), the XLR has a front engine and rear-mounted transmission, helping to give the car a nearly perfect 50/50 weight balance, something the competition can't match. Besides giving the XLR extremely good handling, this arrangement allows for more legroom for the occupants.

At 3,647 pounds, the XLR is the lightest vehicle in its class. Yet it has the longest wheelbase, lowest height, most horsepower and widest track. Trunk space is limited, though. With the top down, it has just 4.4 cubic feet of space; with the top up, that expands to 11.6 cubic feet.

The XLR's chassis is based on GM's new performance car architecture, which the company describes as a patented structure comprising steel hydroformed frame rails, an enclosed structural tunnel, aluminum cockpit structure and balsa-cored composite floors. Among the car's other amenities are a nine-speaker Bose audio system with a six-disc in-dash CD changer and digital signal processing modes, XM Satellite Radio and DVD entertainment system (which operates only when the transmission is in "park"). A head-up display projects speed and other key driving information onto the bottom of the windshield in front of the driver.

All of that is standard; there were no options on our test car, and apparently none are available. The base price of our car was $75,835, and with the $815 freight charge, it totalled $76,650.

EPA fuel-economy ratings aren't bad at all for a car with this much performance: 17 miles per gallon in the city and 25 mpg on the highway. There is no gas-guzzler tax. The tank holds 18 gallons of fuel, and unleaded premium is recommended for the best performance.

G. Chambers Williams III is staff automotive columnist for the San Antonio Express-News and former transportation writer for the Star-Telegram. His automotive columns have appeared regularly in the Star-Telegram since 1995. You may contact him at (210) 250-3236; chambers@star-telegram.com.

At a Glance: 2005 Cadillac XLR roadster The package: Two-door, V-8 powered, two-passenger, high-performance, rear-wheel-drive, luxury retractable-hard-top roadster. Highlights: All new just last year, this is the first true sports car from Cadillac, riding on the same chassis as the newest generation of the Corvette, yet more refined and designed for a more affluent consumer. Negatives: Engine not as powerful as that of the less-expensive Corvette. Engine: 4.6-liter V-8. Transmission: Five-speed automatic. Horsepower/Torque: 320 hp./310 foot-pounds. Length: 177.7 inches. Curb weight: 3,647 pounds. EPA fuel economy: 17 miles per gallon city/25 highway. Major competitors: Lexus SC 430, Mercedes-Benz SL500, Jaguar XK8. Base price: $75,835 plus $815 freight. Prices as tested: $76,650, including freight. On the Road rating: ***** (five stars out of five).

Prices shown are manufacturer's suggested retail; actual selling prices may vary according to manufacturer and/or dealer rebates, discounts and incentives, if any.