Photos: Mercedes-Benz SL63 AMG Roadster

With the AMG treatment, the SL's standard V-8 or V-12 is replaced with a hand-built 518 horsepower 6.3-liter V-8, along with a new transmission and suspension. These vents on the fender serve to remove hot air from the engine compartment.

The front of the SL Roadster and SL AMG gets a redesign, with a single bar across the grille and a new fascia. The black grille is unique to the AMG model.

The active sports suspension in the SL63 AMG prevents body roll, keeping the car flat while cornering.

The SL63 AMG gets special AMG gauges, along with the new three spoke steering wheel common across the SL line. The speedometer and tachometer needles spin to their maximum position then drop back down when the car is started.

Mercedes-Benz makes the SL63 AMG practical in colder weather by including its AirScarf technology. AirScarf uses fans in the headrests to blow warm air around the driver's and passenger's neck and shoulders.

Mercedes-Benz replaced the torque converter in its AMG seven speed automatic with a double-clutch assembly. Mercedes-Benz distinguishes this transmission from Audi's DSG and other double-clutch manual transmissions, pointing out that its transmission can downshift more than one gear at a time, from 7th to 4th, for example, and offers a smoother shifting experience. The transmission as four modes, Normal, Sport, Sport Plus, and Manual. At its fastest, the transmission can shift gears in 100 milliseconds. The SL63 AMG also has launch control, letting you push the gas to the floor, then launch with no wheel spin.

The SL63 AMG gets the same head unit as other SL models. The interface has a menu across the top for with entries for navigation, audio, telephone, and video.

The new audio system in the SL-class gets a 4 gigabyte jukebox, letting you store about 1,000 songs in MP3 format. An SD card slot is also visible above the LCD.