+1 to all that have said use the car as a weapon, just consider if you get too much "debris" under the car/tires, that could ultimately impair movement of the vehicle. Horrible to think of having to mow people down, but that was the mobs choice to block the vehicle, not the driver.
Shooting thru your windshield is viable option. The windshield will not deflect the path of the bullet as much as you think....
You can kiss your hearing goodbye, though. And then you don't have the ability to see through your fractured windshield. Better to floor it if the bad guys are in front, and lower your windows just enough to stick the muzzle out if the bad guys are to the side and you're unable to move.