Because of the 722 S' link to the 722 Coupe, the uber drop top uses a supercharged 5.5L V8, good for 650 horsepower. That stable of ponies is good for a top end in excess of 220 mph, which makes the 772 S one of the fastest convertibles ever built.
Like the rest of the 722 S, the car's canvas top is even a high-speed marvel. Unlike some convertible tops residing atop bona fide, Mercedes claims the SLR 722 S' roof is good for speeds over 200 mph.
The 722 S also uses a carbon fiber body, which gives the convertible enough structural strength to achieve mind-numbing speeds even without the support of a fixed roof. The SLR 722 S also benefits from a 10 mm lower ride height, as well as a recalibrated suspension system.
Only 150 McLaren SLR 722 S's are earmarked for production, with availability beginning in January 2009.