Mercedes-Benz SL63 AMG

The SL63 AMG is the high-performance version of the Mercedes-Benz SL-Class luxury hard-top convertible. With the demise of the V12-powered SL65 AMG, this grand tourer sits at the top of the SL lineup with a mellifluous and potent 6.2-liter V8.

Though replaced throughout much of the rest of the AMG range by a smaller-displacement, twin-turbocharged motor, this V8 makes stirring noises along with plenty of power - 518 horsepower and 465 lb-ft of torque, enough to propel the roadster from zero-to-60 mpg in a claimed (and likely conservative) 4.5 seconds. This powerful V8 is mated to an AMG SPEEDSHIFT seven-speed multi-clutch automatic transmission, which sends the power exclusively to the rear wheels - as it should.

The SL63 features the same new styling that dresses up the rest of the latest SL roadster lineup. Rounded dual headlamps are out, replaced by angular bi-Xenon lamps that Mercedes says are more efficient and powerful than LEDs. With a black background to the lamps and a simplified grill, the SL's face is substantially changed with the facelifted model.

The SL chassis uses a fully independent, double-control-arm front suspension and the standard Mercedes-Benz five-link rear suspension. All SL models come with second-generation Active Body Control (ABC), the Mercedes-Benz active-suspension technology that attempts to eliminate body roll in cornering, squat under acceleration and dive during braking.

Unique to the AMG variants is a highly aggressive bodykit that features front and rear diffusers and multiple vents to cool both the motor and the massive brakes. Standard wheels are 19-inch AMG staggered-width alloy wheels -- 8.5 and 9.5 inches wide -- fitted with 255/35R19 (front) and 285/30R19 (rear) tires. The wheels feature triple-spoke styling and a titanium grey finish.

The AMG treatment also includes a lowered and stiffened suspension and a limited-slip rear differential.

Finished in nappa leather and genuine carbon fiber, the interior features standard AMG sport seats, an AMG three-spoke steering wheel and a sport instrument cluster with red tach and speedometer needles that swing to the max position and back whenever the ignition is turned on.

The SL63, like all SLs, features a folding metal roof. A glass panorama roof remains an option.

Audi R8 V10 Spyder 2012

The R8 V10 Spyder is the convertible version of Audi ’s mid-engined, 10-cylinder R8 supercar. As with its fixed-roof sibling, the R8 V10 Spyder is based on the same platform as the Lamboghini Gallardo and features an excellent balance of extreme performance and docile around-town driving manners. For those seeking a more affordable everyday exotic, Audi offers coupe and drop-top versions of the R8 with a V8.

This 5.2-liter V10 engine delivers an impressive 525 horsepower at 8,000 rpm, along with peak torque of 391 lb-ft at 6,500 rpm. The sprint to 62 mph takes just 4.1 seconds, compared to just 3.7 seconds for the coupe R8 V10.

Accelerating to 124 mph is a similarly brisk 12.7-second trip. Top speed is 195 mph.

Fuel consumption for the six-speed manual version is rated at 12 city, 20 highway mpg. The R-tronic automated manual gearbox improves the city figure to 13 mpg - highway mileage remains unchanged.

Notably absent are the R8's trademark aluminum "side blades." Other visual changes for the Spyder model include additional air intakes located behind the seats as well as a pair of safety roll bars. The placement of the fuel filler cap was also changed due to the lack rear pillars. Changes under sheet metal are focused around chassis strengthening, but otherwise, Audi says the V10 Spyder is mostly unchanged from its hard-top counterpart. Cosmetically, the exterior gains high gloss black air inlet grilles, spoiler lip and rear outlet grilles. Exhaust tips are also swapped for oval tips.

It is worth noting, however, that both the R8 V10 and R8 V10 Spyder feature an aluminum double wishbone suspension which is tuned for higher performance than the suspension found in the 4.2 model.

The convertible top weighs just 93 pounds, helping to keep the car’s center of gravity down low, and can be raised or lowered in just 19 seconds at speeds of up to 31 mph. 

Uber-Audi Features

 Befitting the car's considerable price, the R8 V10 Spyder comes standard with a host of features including a navigation system with 3D maps and a 6.5-inch LCD display, a 465-watt Bang & Olufsen sound system with 12 speakers, fine nappa leather sports seats, a rear parking camera that pairs with ultrasonic sensors and Bluetooth connectivity with seatbelt-mounted speakers for easy hands-free communication.

The V10 Spyder also features Audi's magnetic ride adaptive damping system with manual Sport and Normal sport modes.

Jaguar XKR Convertible

The XKR Convertible is the more performance-focused version of the normal drop-top XK. It packs a 510 horsepower punch and features more aggressive touches to its Aston Martin-like styling.

In addition to its massive horsepower rating, the AJ-V8 Gen III 5.0-liter engine delivers a whopping 461 pound-feet of torque. The sprint from zero to 60 mph takes just 4.6 seconds.

There's not a lot of space for rear passengers, but the driver and his or her passenger enjoy a luxurious grand touring experience with enough power to give most sports cars a run for their money.

The XKR Convertible owes its handsome looks to a unique design approach taken by Jaguar's team. Instead of designing the Coupe first, the design team began by penning the Convertible. This strategy ensured the drop-top doesn't simply look like a coupe with its roof chopped off.

Like its coupe counterpart, the XKR Convertible has unique styling cues such as a more aggressive front fascia, air intakes on the hood, aluminum-finish grilles, more creases on the hood, and quad exhaust pipes. Customers can chose between 19- and 20-inch wheels for the XKR.

The XKR's roof is a power-latching, self-stowing system with three layers including Thinsulate insulation and a Rakona headliner. When the top is down, an aluminum tonneau cover conceals the canvas roof. While many convertibles are only offered with a black roof, the the XK can be ordered with gray, burgundy, green or dark beige canvas.

The XKR's suspension has been tuned for a more aggressive ride. Changes include up-rated springs and dampers, plus a recalibrated computer to control the dynamic suspension settings.

As is the case with the regular XK convertible, the XKR model is built around Jaguar's ultra-strong "Lightweight Vehicle Technology," which does not need traditional stiffening panels to achieve a sturdy body structure. In fact, the XK convertible is 19 percent lighter than the previous-generation XK drop-top.

A six-speed automatic transmission with steering-wheel-mounted paddles is standard. On downshifts, the system creates a throttle blip to shorten over-run shifts. An "active" exhaust system ensures the XKR is quiet while cruising, yet still able to create purposeful V8 roar under hard acceleration.

Although they are not a legal requirement, the Convertible features a Roll-over Protection Device consisting of two aluminum hoops that are automatically deployed if the car's sensors detect the onset of a roll-over accident.

Other standard features include adaptive headlights that swivel in corners, aluminum-finish side window surround, stability control, keyless entry and start, a seven-inch touch screen to control various car functions, and a body-colored spoiler.

Options include a 525-watt Alpine premium sound system, Sirius satellite radio, soft-grain leather, a leather-wrapped instrument panel, and a heated steering wheel.

All XKRs are fitted standard with an iPod and USB connectivity interface, an air quality sensor, front park assist and electrochromic and heated power fold-back mirrors.