I had somewhat of a similar situation, except the guy started harassing me, my wife, and my not even 1 year old daughter for no reason that we could discern.
Scenario: We were driving to the grocery store at 9pm on a Friday night when I noticed the headlights of a GMC/Chevy truck coming up behind us. I'm in the slow lane doing 65MPH in a 55MPH zone with no one else around. Anyway, instead of passing me, the assclown runs up on my bumper and stays there for about 30 seconds. There is what I'd estimate is less than two feet between our vehicles. I don't do anything except maintain my speed, and even sped up at one point, but he had more power than me. If I tap my brakes he's likely to hit me and injure my baby daughter. So, he whips around me and starts weaving in and out of his lane, forcing me to hit my brakes and almost off the road. Then, he gets in front of me, starts slowing down, and then slams on his brakes. We almost come to a stop and I'm ready to poke holes in whoever pops out of the car, but instead of stopping he speeds off.
By this point, I'm pissed, but I have my wife and duaghter in the car with me. I follow him long enough to get his license plate number. Had I been alone, I would have followed him to the pool hall he and his friends went to and put my hands upon him, but this was not an option. The next Monday night, I pulled the registration of the car and the license information for other people who lived at the home, since it didn't seem to be the type of behavior of a 50 year old man. He has a 16 year old daugher and an 18 year old son who appears to fit the description of who I saw driving. I call the person who owns the Tahoe up (his name is Randy) and the conversation goes like this:
Randy: "Hello?"
Me: "Excuse me sir, but is this Randy XXXXXXX?"
Randy: "Yes it is."
Me: "Sir, you do not know me, but according to my records, you own a 1997 Chevy Tahoe SUV. Is this correct?"
Randy: "Yes. What exactly is this about?"
Me: "Sir, were you driving that vehicle on Friday night?"
Randy: "No sir, I was not. My son was driving it out with his friends. Again, what is this about?"
Me: "Well sir, on Friday night I was driving to the grocery store with my wife and my baby daughter to pick up some items when someone driving your Tahoe nearly ran me off the road repeatedly. Had I been on the job, your son would not have come home and you would be without a vehicle. He's luckier still that I didn't take his actions to be a threat against the lives of myself and my family."
Randy: "I see..."
Me: "Sir, I've had some time to think about it, and I've calmed down since Friday. But, I figured you should be informed that your son was endangering the lives of my family, as well as abusing your expensive SUV."
Randy: "I appreciate that."
Randy in the background "Boy, get your ass in here, now!"
Randy: "How did you get my information?"
Me: "Sir, that's what I do for a living. Thank you for your attention in the matter and good night."
It was the first day of summe, and this kid was a year behind, so he had just become a Senior. I think I put a damper on his summer.
Remember the Alamo, and God Bless Texas...