Mercedes’ new super sports car being developed with its racing partner HWA and the next-generation SL due in 2012 will adopt aluminum bodywork construction in an effort to save weight. Similar to the construction of Jaguar’s XJ and Audi’s A8 saloons, the adoption of lightweight aluminum will improve the handling, ride, performance and fuel economy of Mercedes’ new models.

The new sports car, which is rumored to be called the SLC, will arrive in 2010 and will be followed two years later the by the new SL, according to AutoWeek. Both cars will be front-engined and RWD and share most of their components, including drivetrains, suspension and electrical systems.

The SLC will be built in low volumes at a new factory in Germany by HWA and feature a welded-aluminum spaceframe. The final design of the car is still under wraps but it’s thought that it could either feature a retro look based on the 300SLR of the 1950s or a more modern design similar to the SLR.

Meanwhile, McLaren is said to be working on its own supercar project in the UK. Codenamed P11, the new McLaren model is due to hit the streets in 2010 and is rumored to be an unfinished project started by F1 designer Gordon Murray, who left the company in 2004 to start his own firm.