The development of the Mercedes-Benz 300 SL began in 1950, when Mercedes-Benz began to think about a return to racing. In June 1951, the Board decided to resume participation in racing events from 1952 on, and gave the final orders for the construction of the 300 SL. This car was not sold to the public, it was built just for racing.
The Sauber-Mercedes C 9 racing sports car was the outcome of a longstanding innovation partnership between Mercedes-Benz and the Swiss racing team established by Peter Sauber, a relationship that dated back to 1984. That was the year in which the Stuttgart company and the Zurich-based racing car designer reached an agreement for Mercedes-Benz to supply engines for the Sauber prototype sports cars used in the Group C motor racing series.
After the successful W 25 Grand Prix racing car, Mercedes-Benz developed a new car for the 1937 season. The new W 125 racing car had an extremely sturdy, tubular oval frame made from special steel, with four cross members. It benefited from tests with production car frames as, for instance, the one used on the 1938 generation of the Mercedes-Benz 230. The wheels were located differently, by double wishbones and coil springs at the front, as on the celebrated, noble 500 K and 540 K models, and by a double-joint De Dion rear axle which ensured constant camber, plus longitudinally installed torsion bar springs and lever-type shock absorbers. Lateral links transferred thrust and brake moments to the chassis.