I notice something. When the other car smack some of y'all's car, and y'all were inside your own car, y'all don't come out and question the other father sucker. Why not y'all just come out and give that asshole a piece of your mind... and then a piece of your pipe, or baseball bat, or whatever shit you have that will dent his car.
If it was me, I would straight come out and see. If there is a dent, I will make him pay. If he doesn't want to pay,
1) just tell him to be careful cos personal information can be obtained easily. Then smile and walk of.
2) don't bother but come back in about 10 or 20 minutes time to see if his car is still there. If it is, use a fish scaller and scratch his car.
3) don't bother at all. Be at peace and just tell him that he's a fucked up asshole. After your shopping or whatever, go back to your car. If his car is still there, use a glass cutter and slash his front wind screen nicely. Unsure if this will work but sounds delicious, especially when he's driving fast and the window just shatter.
I'm not sorry to say this but to me, purported ignorance or direct ignorance has a bloody fucking heavy price to pay, especially when our laws are just as fucked up as those who are ignorance on purpose.