Oh Absolutely, they're tough!

I might worry about pepper plants left in the car, but unless you think they'll be stolen by a passing pepper thief I wouldn't worry.

Should be no problem unless you leave your car keys with them.

I would ask "What are you going to do with them ?" If your making salsa or cooking them in a few days sure, but if you plan on preserving them like canning or freezing I would run from the garden to the kitchen.

Probably. They're pretty hearty little peppers and will last forever in my fridge. I don't see why a couple of hours in the car would hurt them, though I wouldn't recommend leaving them overnight in case they freeze (although if you are in a portion of the country where it is no longer freezing, this won't be a problem) or in case the extended exposure to heat makes them go off.

how hot is the car? Don't see any health reason why they cannot sit for a few hours in the car as long as it is not 150 degrees or some such.