Have a crowbar handy. It's known to be useful in a variety of situations, including a literal space alien assault.
A small charge of C4 works wonders. Just be sure to lay your head over in the passenger seat before detonation.
I carry a small hatchet in the trunk of my car with the spare tire just for this reason.
But also don’t leave it loose in your vehicle. A crowbar hitting your head in a car accident does not sound like a good time.