He decided to support both the new company Auto Union, who took over Porsche's concept, and Mercedes-Benz, who had more than a quarter century of experience in major international racing.

These popular uphill races were usually dominated by the superior traction of the mid engine Auto Union of Hans Stuck, who won[7] at Felsberg [de], Kesselberg, Freiburg Schauinsland and Mont Ventoux.

The 1934 Belgian Grand Prix was held on the Circuit de Spa-Francorchamps which then had a tight corner named after the nearby Ancienne Douane, the old customs station at the former border with Germany.

Nuvolari famously won the 1935 German Grand Prix, but his Alfa Romeo was the only non-German car to win a European Championship race from 1935 to 1939.

By driving the race car himself, young engineer Rudolf Uhlenhaut determined that the W25 had a too stiff suspension in a too soft chassis, which made handling difficult.

For the 1937 Avusrennen,[12] two Streamline V12-powered W25K[13] were entered, as weight and handling was of low importance at the AVUS which had been fitted with a banked north turn.

[16] As part of a partnership between Mercedes-Benz and Nintendo, the Wii U game Mario Kart 8 and its Nintendo Switch port Mario Kart 8 Deluxe feature a W25 Silver Arrow as a playable in-game vehicle, added as part of a post-launch downloadable game update on August 27, 2014.