Müller stepped up from karting in 1995, and finished third in BMW Formula Junior driving for Abt Sportsline.

[1] Müller stepped up to International Formula 3000 for 1998 driving as a BMW Junior for the Oreca team, but only finished in 20th position.

He then returned to the German championship in 2000, and finished as runner-up to Giorgio Pantano, driving for Team Ghinzani.

He competed at two NASCAR Craftsman Truck Series short tracks before the end of the season.

After sitting out the 2006 season, Müller once again raced in the Spa 24 Hours, this time for Scuderia Playteam Sarafree, finishing 18th in a Maserati MC12.

At the fifth round at Spa-Francorchamps, he replaced Alexandros Margaritis at Triple H Team Hegersport and reached for them until the end of the season.