Found this, in case no one wants to take 1 out & look @ it-
http://www.youtube.com/watch?v=L9Le6Mvqez8
Lots of Audi stuff here-
http://www.youtube.com/profile?user=bajiee&view=videos
If you're just starting out-
http://www.youtube.com/watch?v=K4JhruinbWc&eurl=http%3A%2F%2Fjalopnik%2Ecom%2F5335841%2Fhow%2Ddoes%2Dthe%2Ddifferential%2Dwork&feature=player_embedded