Originally Posted by Yacht Master
Just MB and Audi, any body know?
GM through it's Opel division last raced from '00-'05. They pulled out due to their lack of competitiveness and the company's financial troubles.
BMW did previously race in the DTM in the 80s, along with Ford and Volvo! The predecessor to DTM was Group A. They left the series after MB managed to block BMW's effort to convert the series to V8 instead of the V6 if I recall correctly.
BMW then moved to supporting touring cars where they've been an active supporter ever since.