Not to be confused with the power output of the car, which stands at 650hp (478kW), the odd ‘722’ labeling came from a race in 1955 in which Stirling Moss competed in a Mercedes Benz 300 SLR. The start time for Stirling Moss was exactly 7.22am.
The body of the 722 S, with the exception of two aluminum frames, is completely made of carbon-fiber materials just like the hardtop. It also features the same 650hp (478kW) and 604lb-ft (820Nm) output from a hand-built 5.5L supercharged V8.
The five-speed automatic carries over from the standard SLR lineup but has been specially configured to accommodate the engine's very high torque, and allows the driver to choose between two sets of shift characteristics. As a result the SLR Roadster 722 S sprints from 0-62mph (0-100km/h) in just 3.7 seconds, and 124mph (200km/h) is reached in 10.6 seconds.
Despite undergoing an extensive weight saving program, the 722 S still features a fully retractable folding roof designed to withstand the extreme speeds the car is capable of. The weave structure of the roof material reflects the carbon-fiber look of the car’s aero kit and remains completely stable even at the car’s top speed of 209mph (335km/h). For opening, the roof needs to be unlatched at the windscreen frame and lifted slightly, after which it folds down electrically in just ten seconds.
The car’s spring and shock absorber configurations are also stiffer, and the body has been lowered by 10mm at the front and rear. Other distinct features include lightweight 19in forged aluminum wheels housing red-painted brake calipers and carbon-ceramic discs.
Interior features include two-zone automatic climate control, a Bose sound system, a multifunction sports steering wheel with shift paddles and a navigation system with an integrated radio and CD player.
First sales will start in Europe in January, with pricing around the €517,650 mark (about €25,000 more than the standard SLR Roadster) and only 150 units will be built in total. North American availability and pricing is yet to be announced.
Meanwhile, the final variant of the SLR, the upcoming Speedster, is expected to make its world debut at next year’s Detroit Auto Show.