Mercedes-McLaren Take the Lid off the SLR

Mercedes-Benz has an interesting philosophy on its fastest vehicles: it builds them in extremely limited quantities, and then at a later date, offers them once more, but without a roof. This practice has yielded a number of vehicles that expose occupants to open air at highly ludicrous speeds. First, there was the CLK-GTR, which was the homologation road going version of the competitive Le Mans car (sans roof). It was followed up by another variation of the CLK, the CLK DTM, a highly modified production CLK that mimicked the look and to a degree, the performance of the touring car. The latest Mercedes supercar to shed its roof is the modern-day incarnation of the "silver arrow" racer, the Mercedes-McLaren SLR.

Almost everything we've come to love about the SLR has remained present on the roadster. The slender and elegant F1-inspired bodywork with its copious vents is all intact, right down to the electronically operated air-brake and spoiler. While the gullwing doors of the CLK-GTR were lost inthe convertible conversion, the SLR maintains its unusual doors that open upwards and outwards like an insect's wings. Mercedes-Benz says that the SLR's carbon fiber monocoque chassis has a rigidity that's "hitherto unattained in open-top vehicles." This means that as it stands, the SLR Roadster holds the title as the world's most rigid open-top vehicle, even though Mercedes didn't reveal what the SLR Roadster's chassis stiffness is in numerical values. Though the chassis didn't need to be any stronger, the SLR's A-pillars are made of steel to protect the occupants if the vehicle rolls over, and a rollover protection system was added.

Best of all is the SLR's engine. It's the big, burly supercharged V8 that spits out 626 horsepower through the rear wheels via an AMG Speedshift R automatic transmission. With not muchweight to haul about, the SLR Roadster can sprint to 60 mph in well under four seconds, which is quite a bit less time than it takes to lower the SLR's cloth roof; that process takes less than ten seconds. Unusual for a car of this price, the roof isn't completely automatic; the driver must still unlatch it by hand and push it upwards before the electric motors can take over, much like the Chrysler Crossfire. Still, that's not much to ask from a vehicle whose cloth roof can withstand speeds of over 200 mph. Hours upon hours of aerodynamic tuning ensured that the Roadster is just as fast as the Coupe, and that regular conversations can occur with the wind down at speeds of up to 125 mph.

Only a handful of customers will be able to purchase the McLaren SLR Roadster when it goes on sale in September, but if you're truly interested in one, visit a Mercedes-Benz retailer for more details. Like the regular SLR, the Roadster won't be built in Germany, but rather at McLaren's F1 race car facility in Woking, England.