Its absolutely true. In the UK at least, if you are cut up, tailgated or otherwise generally hassled on the road, there is a way better than average chance that the moron doing it is behind the wheel of an Audi.
Audi's ads seem to play on this, too. While others seen to concentrate on the economy|, safety or confort of their products, Audi's ads are clearly aimed at the knuckle draggers.
Happily all the BMW jokes translate nicely into Audi jokes, though.