Yesterday, I got honked at, (again) by a car (taxi) driver. Apparently, I deserved it, because I rode on the road and the car driver had to slow down slightly because there were other cars coming from the other direction and therefore she/he couldn't overtake me immediately. So he (yes, I strongly suspect it was a he) communicated his disapproval by honking long and fervently. I, in return, extended my arm, then my middle finger and held it in that position, long and fervently.
By the way, here's some interesting statistics of the makes/models of cars rude car drivers drive, in my experience, from this year (2010):
1) Volvo V70 (black) - 100%
2) -- (0%)
3) -- (0%)
Total number of incidents: 2