In the city I reside in, trucks are targeted specifically because many truck owners have guns in the glove box. Just because you have a gun doesn’t mean you’re always around to use it.
In high school, my driver's ed instructor (here in California) said (jokingly) if you screw up and hit a person, you better hope they die. The implications of a death on your hands is a bounded lawsuit / jail problem. Someone surviving is a much less constrained problem. While crass, it made a point.
If you shoot someone in self defense and they are killed, you are dealing with voluntary manslaughter as the most likely charge, argue accordingly. If they survive, they get the opportunity to muddy the waters.
Either it is on your person or locked in a safe.