This thread is pretty hilarious, it really displays how trivial full fledged arguments can get over something so trivial. However, has this type of thing happened to me? Yes. Was I unhappy? Yes, while I used to get upset and probably swore, I never would think about retaliating since it won't make the slightest difference to that one driver in the long run. A couple of those times, I actually pulled over, got my QD and a microfiber towel out, and wiped down the front of the car lol. I got plenty of bewildered looks from people driving by.
IBTL!
PS. Didn't you just get your entire windshield much dirtier when you sprayed what looks like a gallon of washer fluid on it to retaliate?