I'll look for links, but Formula 1 used to have AWD cars, until it was banned. Audi dominated BTCC when its B5 A4 was racing, also in DTM they are very successful, Audi is currently ahead of Mercedes in DTM, Porsche has been using it for a long time. What about Audi in Trans Am? People use it where ever it is not banned. Wonder why they keep banning them if they do so well with it? Here are just a few:
McLaren
http://upload.wikimedia.org/wikipedia/commons/thumb/c/c0/McLaren_M9A.jpg/180px-McLaren_M9A.jpg
Ford Cosworth
http://farm2.static.flickr.com/1013/3166716966_ae7d6cda61.jpg
Trans Am car
http://farm4.static.flickr.com/3219/2750530981_aa9595b83c.jpg
BTCC
http://farm3.static.flickr.com/2007/2128363640_42818edf5c.jpg
DTM
http://farm4.static.flickr.com/3190/2909746042_938cc6b76b.jpg