As part of the European Formula 2 Championship round at the Jim Clark Race at the Hockenheimring, a round of the International German Automobile Racing Championship (IDRM) was also held on April 10, 1983. With the introduction of the FIA Group C in 1982, the regulations primarily permitted Group C sports prototypes in accordance with Appendix J of the International Sporting Code. However, since not enough vehicles of this category were available at the start of the new era, Group 6 sports prototypes remained eligible to race. The previously dominant Group 5 silhouette cars, such as the Porsche 935, Ford Capri Turbo, or BMW 320 Turbo, thus largely disappeared from the championship.
For the Warsteiner Team Joest Racing, His Royal Highness Prince Leopold of Bavaria competed with a Porsche 936/80 – one of the last successful Group 6 sports prototypes. The open-top race car was powered by an air-cooled 2.142-liter flat-six engine with two KKK exhaust turbochargers, which produced around 620 hp. Despite its concept being several years old already, the Porsche 936/80 was still competitive and able to hold its own against the modern Group C competition. Behind two Group C prototypes, Prince Leopold of Bavaria crossed the finish line as an outstanding third overall.