I myself witnessed a fast food road rage about 15 years ago.
I pull into the Buger King drive-thru at about 1:30 in the morning on a Saturday.The guy in the car in front of me is yelling and pointing at the pay window;I don't have any idea what it's about.
He get his food,yells something,and starts to pull out.Here is where it gets fun.When you pull out,there is a curving curb,so you have to make a gentle right or you'll hit it.He didn't,and he did.
He throws the car into reverse,backs up to thw window and starts screaming.One of the kids said something to him that enraged him even more(I'm guessing something along the lines of FU,lol),and he hops out of the car and continues his raging.
He gets even more angry,and reaches in and attempts to grab one of the teenagers.
BIG MISTAKE!!!
After lunging into the window several times,THEY grab HIM,and drag his butt in through the window.At this point,I'm laughing so hard it hurts.I pull up to the window,and see a very cowed tough guy cornered by four very pissed off teenage boys.
The kid hands me my food,and I ask,"what are you gonna do with him?"
The kid says,"Oh,we already called the cops,they're on the way."