This is why angrily honking at folks is ill-advised, and if honked at inappropriately, giving the finger in return is a bad idea. The most I’ll do these days is wave excitedly, as if I’d seen a long-lost friend, if I get honked at inappropriately.
I refer to the waving excitingly gestures as a flock (middle finger gesture) of these. It gets me in less trouble. I also refer to my middle finger as my driving finger.