i kind of agree with the last few. that's the kind of thing i'm always tempted to do, but invariably when i react like that i later bump into the person in question at work or in some kind of awkward social situation and i think "man if i hadn't tried to out-a$$hole that guy we would be getting along fine right now". once you get face to face with someone it suddenly occurs to them that you're a person and they invariably feel stupid if you were decent when they acted like cavemen (or cavewomen, in this case).
one reason to take the high road.
oops one edit here. when i say "the kind of thing i'm always tempted to do" i mean retaliating to nasty drivers, not "people riding". i don't find people riding overly tempting.