I often have students ask me about what to do if they are attacked at a stop light by a carjacker or irate driver. They are sometimes shocked when my answer doesn't involve a firearm!
Here are some things I tell them:
1) Don't drive like a jerk & piss people off!
2) If another driver becomes angry with you, don't engage them. Even detour your route if needed.
3) While stopped, pay attention to what is going on around you.
4) Keep your doors locked.
5) Keep your windows up, at least while stopped.
6) Leave yourself an escape. A good rule of thumb is being able to completely see the rear tires of the vehicle in front of you. This will give you enough space to escape , or at a minimum get the vehicle moving!