Gass graduated from the University of Darmstadt with a degree in electro-mechanical engineering in 1982. In 1990 he joined Audi AG to work in the braking system development department. By 1991 he moved into the motosport department, before soon joining the Bugatti programme. Between 1994 and 2001 he worked as a track engineer on Audi Sport projects, as the team won the 24 Hours of Le Mans in both 2000 and 2001. He then moved into Formula One with Toyota and Lotus until 2012, when he returned to Audi as head of racing, playing a key role in the victory in the World Endurance Championship in 2012 and 2013 and heading up the German touring car series (DTM), Formula E and World Rallycross teams. In 2017 he replaced Wolfgang Ullrich as head of Audi motorsport. In 2017/18, in his first season as team principal, Audi won the Formula E constructors’ championship.