Now races in sportscars (including Blancpain and FIA GT), and other endurance racing in Germany, including the VLN Endurance Championship, as well as drift challenges, however his racing is somewhat limited due to his lack of funds, which also affected his single-seater career. That said, he competed in the European Le Mans Series in 2020. Muller mainly works as a racing driver instructor, a coach for young racing drivers and a instructor and consultant for Porsche. He won the 1996 German Formula Renault series, and although he has been mainly in either GT's or single-seaters, he did have a spell, in 2003, of driving in the NASCAR Craftsmen Truck series. Now lives in Switzerland.

Biography last updated 22 Feb 2020