After gaining a degree in aerospace technology, he joined Ilmor Engineering in 1996, developing both Formula One and CART engines. In 2000 he joined Toyota Motorsport, initially working on engine design and development, before becoming F1 Operations and Team Manager in 2008. After Toyota exited Formula1 at the end of the 2009 season, he was as General Manager Business Development, Operations & Production.
- "Mario Theissen to hand over to Jens Marquardt on 1 July 2011". BMW. 24 November 2010. Retrieved 2010-11-24.