What I do now, if someone passes me too close, is I describe a very small fish with my hands, shake my head, and spin my finger around my temple.

In fact when anyone does anything near me I give them this really disappointed head shake that I hope they are looking through the rear-view mirror at. Its a kind of passive insult in a way and the drivers (if they are looking through their rear-views, which I doubt they are) feel like an idiot. At least I feel like an idiot when people do that kind of thing to me when I'm being an idiot. Either way it doesn't make me angry to do it.

Now that I re-read this, it sounds pathetic, but whatever.