When Cadillac introduced the XLR sports car in 2004, the company stressed the fact that its first two-seater since 1993 would not be a volume vehicle. That’s certainly true. But it seems that Cadillac would like to move more XLRs than it is now: According to Automotive News data, the company sold 465 XLRs in the first three months of 2007, about half the number sold in the first three months of 2006.

Compare that with the 8,176 Chevrolet Corvettes sold in the first three months of 2007, and it would appear that the XLR is more exclusive than Cadillac ever intended. That Corvette/XLR comparison is valid, as both cars share basic chassis components, and both are made in the Bowling Green, Ky., plant that previously produced only Corvettes.

I’d submit that the XLR is more a victim of the times than anything else, because it’s an excellent car. But it’s also quite expensive — the hot-rodded XLR-V model we tested lists for a cool $100,000, with $1,700 of that going toward the federal “gas-guzzler” tax, because the XLR-V gets an EPA-rated 15 miles per gallon in the city, 22 mpg on the highway. And that’s premium gas, of course. With even regular gas again knocking on that $3-a-gallon door — or in some states, already barging right through it — the term “gas guzzler” is hardly a selling point.

That said, the regular XLR model isn’t saddled with the guzzler tax. Its engine, a 4.6-liter, 320-horsepower Northstar V-8, gets 17 mpg in the city, 27 mpg on the highway. Plus, the XLR costs about $20,000 less than the XLR-V.

So what’s the big difference? Mostly it’s under the hood: The XLR-V has a supercharged 4.4-liter V-8 that has a sobering 443 horsepower, slotting it right between the regular Corvette (400 horsepower) and the fire-breathing Z06 (505 horsepower). With its perceptive six-speed automatic transmission, the XLR-V can go from 0 to 60 mph in less than five seconds, and does so with authority and Corvette-caliber stability.

But really, though, Cadillac insisted from the XLR’s inception that performance was secondary to the luxury-car aspect — comfort, features, quality of leather stitching and wood trim, that sort of thing. So though a 443-horsepower Cadillac is a neat thing, the XLR-V does sort of depart from the XLR’s original mission.

That said, it’s fun to be in the driver’s seat when it departs right on down the road. The magnetic-controlled suspension anticipates every bump and pothole, brakes are excellent, and handling, though not at the Corvette Z06 level, is impressive. What the XLR-V does best is down-the-highway cruising, with the retractable hardtop down, and the V-8 engine burbling along.

Inside, the XLR-V is roomy enough for two adults, and the trunk is adequate with the top up. With the top down, though, trunk space drops to 4.4 square feet — at the touch of a button, the top folds itself into part of the trunk — so figure on soft luggage for a weekend trip.

The XLR and XLR-V are 177.7 inches long, about 3 inches longer than a Corvette. At 72.3 inches in width, it’s a third of an inch narrower than a Corvette. The big difference, though, is weight: The Cadillac is about 600 pounds heavier than the Chevrolet, so it’s no surprise the XLR isn’t quite as light on its feet as the Corvette.

I’m not sure how long Cadillac plans to keep the XLR and XLR-V in the lineup. Certainly the car doesn’t get the respect, or the sales, it deserves.