Top 3:
1. Rednecks in pos pick-up trucks. Most dangerous around here and most prone to violence.
2. Inattentive chicks in SUV's. Dangerous as they are completely clueless and should not have licenses.
3. "Boy Racers" 16-25 in just about any car, usually 2-3 of them per car. Usually just yell at you and throw things.

Surprised by the Audi problem. Most, but not all, people around here (Western PA) with nicer cars seem more courteous.