I had a friend who rode on major highways often and had the same issue with people passing so close he could touch them. His solution, though I wouldn't personally advise it, was to slam his fist into the car (he wore armored MC gloves when he rode). One day he slammed his fist into a pickup passing him stupid close. Driver intentionally crashed him and called the cops because he dented his truck (he thought he was in the right). Cops arrested the driver of the pickup with a laundry list of charges including - reckless driving, assault with a deadly weapon with intent to harm, road rage, unsafe passing, unsafe lane change, driving without insurance, and a few others. I was there for part of the argument the pickup driver had with the officer, and as he was arguing with the cop mid arrest the cop basically said "If you were close enough for him to punch and dent your truck, you were way too close and in the wrong." Cop was practicing zero tolerance with this dude lol.
No real point here, just sharing a memory you dug up from my brain lol.