Yeah, DH pounded the side of a car that was yelling at me, who was in front and riding inside the white line of a wide shoulder, about 3 miles from our house, a couple of summers ago. I was doing absolutely nothing wrong. The guy almost hit me on purpose and just went nuts. He pulled over and motioned for us to stop, so we did, thinking we could educate him. Yeah, right. DH called him a 2 word swear, while I calmly said I was following the law, which enraged him even more. He was going to "fight" my DH, which was laughable (he would not have won), as it would have been a battle between 2 middle aged high tech geeks. Anyway, the guy had his young teenaged son in the car, who was mortified, and told his dad to get going and give it up.
After that incident, we have not had any more car punching.