DTM
For 2004, Frentzen moved to the German Deutsche Tourenwagen Masters saloon car series to drive for Opel, encouraged by the success achieved in the series by fellow F1 refugee Jean Alesi. Unfortunately his Opel Vectra was not a competitive car, and he was regularly outpaced by not only the Audi and Mercedes drivers but also by his Opel teammates, eventually finishing the season 14th in the championship standings. However he remained in the DTM with Opel for the 2005 season and finished the year in 8th as best-placed Opel driver, with his best result a 3rd place from pole position at Brno in the Czech Republic.
After Opel withdrew after the 2005 season, Frentzen joined Audi for 2006. He would finish 3rd at the first race of the season at Hockenheim and again at the 8th race of the season at Barcelona. Frentzen finished the season 7th in the final standings and quit the team stating he had "no support from the team".
Read more about this topic: Heinz-Harald Frentzen