Same thing happened to my car about 5 years ago,2 guys on the side of the road threw a beer bottle at my car as i drove past,it landed on the bonnet of my freshly painted car,candy colour at that... :D
but in this case i stopped, got out,and gave chase with my crowbar i had by my seat :P:
cops came,i was charged with an offencive weapon and assualt,but those 2 had enough of an idea not to repeat to someone else's pride an joy....went to court, the 2 guys didnt turn up to give evidence,so i was put on 2 years supervision only...WORTH IT :)