This is something I struggle with; the logical side of me knows that nothing good will come from confrontation with a car and the best policy is to smile and go about my day. At the same time, I do have a temper and it tends to come out when people do something grossly stupid that endangers my life. I've had a few less than stellar moments where I behaved poorly and ended up in some form of confrontation. In retrospect, I always feel ashamed and embarrassed about the incident and I've continually been able to improve my reactions and do the smart thing. It takes a great effort of will for me.
I'm against violence because I have too much to lose in an incident, but some people really need a swift kick to the head.