In 1980, Mercedes-Benz began to take its participation in World Rally Championship competition seriously, embarking on an ambitious project to turn the R107 platform 500 SL convertible into a dominant rally car. The experiment ended when Mercedes executives pulled funding prior to the start of the 1981 season, but not before four prototypes were built.
Power came from the same 5.0-liter V-8 used in the 1980 car, which produced approximately 320 horsepower and shifted through a four-speed automatic transmission. The driver could select gears manually; and to enhance grip, the limited-slip rear differential would also offer up to 80-percent locking. The rally car’s 1:4.08 gearing made for quicker acceleration, but limited the car to a top speed around 135 MPH.