Best way to handle this situation for the safety of all parties involved would be one of the nonviolent options.

But...

If you are one of those people who has to get violent, this might not be a bad option. I say that as opposed to kicking their door, pulling out your u lock, flashing your piece, spraying pepper spray into their window, etc. You have to remember though that the car is a potentially lethal weapon. There are numerous stories of people intentionally using their car to kill someone. And we've all had our days when we just were not going to take it anymore.

You have to take whatever action allows you to leave this situation without letting it be something you mull over, something you regret. I've challenged people to a fight three times in my life. Once for being spit on, once for being hit with a rod rolled up in a newspaper, and once because the guy called my girlfriend a bad word in earshot. I don't regret any of these three altercations and in fact they are a point of pride in my mind. In all three instances the guy never spoke another word to me ever again. Some people need tough love to get the message. By standing up and saying "I won't take this" you may prevent them from doing this to another person. Just make sure you have really and truly been wronged like in my three examples, otherwise you could end up looking stupid.