after racing in the final year of the v8star series in 2003, finishing third behind pedro lamy and thomas mutsch, he switched to the fia gt championship for 2004 with konrad motorsport (in a saleen s7r). for the 2005 season he began racing a maserati mc12 for his own bartels motor & sport team under the vitaphone racing banner, alongside compatriot timo scheider. andrea bertolini replaced scheider for 2006 and the pairing won the championship in 2006, 2008 and 2009. bartels also won the spa 24 hours in 2005, 2006 and 2008.