Here in Arizona we have the "stand your ground" law, and if your car were to be "attacked" by somebody
with a "weapon" you could legally step out of your vehicle and confront the attacker. If the maniac came
at you it would be legal to blast him/her.
If I were able to motor away from the attack on my car I would, but if I were unable to do that I would
not want to stay confined in my car waiting to find out what was next and I would "step out" and engage
the attacker [with my 10MM]; all perfectly legal.