Audi has already challenged exotic sports cars from Porsche and even Ferrari with the R8, a two-seat coupe with cutting edge looks and razor sharp handling. The German automaker upped the ante with the R8 5.2 at Detroit. It can rush to 62 mph in 3.9 seconds and reach a top speed of 196 mph, according to Audi. It goes on sale in Europe in the second quarter of 2009, but a U.S. on-sale date hasn’t been set.

This neat little roadster will appeal to buyers who want the ultimate driving machine. The 2009 Z4 has more power, new styling and a retractable hardtop that motorizes into the trunk in only 20 seconds. The base trim gets a 255-horsepower 3.0-liter 6-cylinder engine carried over from the previous model Z4. Performance fans looking for more get-up-and-go will be happy to hear that BMW is also offering this new roadster with a 300-horsepower turbocharged 6.

Bentleys have more power than most drivers know what to do with. Any Bentley with the word “Speed” at the end of its name is even more powerful. This new convertible is the latest in the boutique British firm’s line of outlandishly fast cars. It puts out 600 horsepower from a 6-liter 12-cylinder engine and will sprint from 0 to 60 mph in 4.5 seconds – 0.3 seconds quicker than the standard GTC. Plus, it has a top speed of 200 mph with the top up and 195 mph with the top down.

This battery-powered rear-wheel-drive performance coupe can go 150 to 200 miles on a single charge, zips from zero to 60 in less than 5.0 seconds, and has a top speed of 120 mph. While that last stat isn’t so sexy, this little roadster is very stimulating. It’s basically an unaltered re-badge of the Lotus Europa adorned with Dodge’s signature crosshair grille. It is powered by 200 kW electric motor, lithium-ion battery pack and a sophisticated controller to manage the energy flow. The trio works to develop an impressive 268 horsepower and a neck snapping 480 lb-ft of torque.

When the Karma goes on sale in November for $87,900, it will be the first mass-produced plug-in electric vehicle sold in the United States. It will accelerate from zero to 60 mph in 5.8 seconds and have a top speed of 125 mph. The Karma S, its convertible counterpart, will use the same mechanicals but have a slick drop-top. As with the Karma, the S will be powered by two electric motors that send 408 horsepower and 959 lb-ft of torque to the rear wheels.

Seemingly buried among the slew of electric vehicles was a pair of the most powerful Mustangs ever, the 2010 Shelby GT500 coupe and convertible. The all-new GT500’s updated 5.4-liter engine will develop 540 horsepower, 40 more than the current model. Set for release this spring, this new pony car gains design and interior cues from the updated standard Mustangs, and chassis and power upgrades from the ultra-high-performance 2008-09 Ford Shelby GT500KR. Among the interior upgrades are satin aluminum trim, a soft-skin dash and suede-like Alcantara material on various surfaces.

The XFR replaces the XF Supercharged as the top cat in the Jag lineup. It’s armed with an all-new 510 horsepower 5.0-liter V8 that propels the vehicle to 60 mph in a mere 4.7 seconds. And even though top speed is electronically limited to 155 mph, Jaguar has managed to achieve 225.675 mph with this car on the famed Bonneville Salt Flats. It also features two new systems, dubbed Active Dynamics and Active Differential Control, which both work to counter wheel slip, whether from a lead foot and giant torque or simple driver misjudgment.

While not your typical family car, the Quattroporte is, in fact, Maserati’s entry in the family car segment. Now, the Italian automaker is upping the va-va-voom factor with performance and styling enhancements sure to appeal to style-conscious parents looking for the ultimate Italian four-door to stand out from the gaggle of Bimmers and Benzos at the local PTA meeting. The engine in the Sport GT S is the same screaming 4.7-liter V8 used in the “S” version, only slightly more powerful – it has 433 horsepower, versus 430 horses. The six-speed automatic transmission’s management software and suspension have also changed to improve driving enjoyment.

Though it won’t be available in the United States, this 650-horsepower, 217.5-mile-per-hour open-top roadster will be one of the world’s most exclusive supercars. Production of the SLR McLaren on which it is based will end in May, making the Stirling Moss edition one final variant to outdo all the others. Only 75 will be built, and only current SLR owners will be considered for the privilege of plunking down 750,000 euros (that’s over a million bucks) to purchase one.

Boasting a top speed of 140 mph while managing to get a claimed 55 mpg on the highway, this turbocharged 2.0-liter diesel concept puts out 180 horsepower and 258 lb-ft of torque at just 1750 rpm. Coupled to a 6-speed double-clutch transmission, the TDI engine launches to 60 mph in 6.2 seconds. Vehicle weight is kept to a minimum (2,600 lbs) through extensive use of aluminum and other lightweight materials.