Not to be racist but all road ragers I've personally come across are middle aged white guys.
I rage like crazy. But it's usually for legit stuff. I do admit that I usually find myself raging at taxis and cars that push into a line of traffic from an illegal point. Taxis cause chaos wherever they go.
Are you sure you didn't do something to make this guy get upset? I have seen people do some really bad things such as cutting off people in their blind spot, or veering into other lanes. I give them the wake up gesture and they always look so puzzled. People zone out in their cars, or take chances.
One thing that I have noticed, people tend to push into the lane next to them if there is any sort of obstruction in their lane (such as a taxi picking up passengers). If that happens, you don't have right of way to push into the lane next to you. I have had to make way for people pushing in in this manner.