I have most of that stuff in my car. We camp. We hike. The tarp's for hanging over picnic tables or for spreading out to catch the mud and junk. Shake it out, fold it back up, it's ready to go. Duct tape and electrical tape for repairs. Plastic bags for wet clothes and junk (I carried more a few years back when it was a question of kids' swimwear, t-shirts puked upon, etc.). We used to have red and yellow tape back when the kids were in soccer, for making quick field markings during practice.
I don't normally carry ID and stuff in the car, but I know people who keep it in the console. It's also pretty common among hikers etc. to leave ID locked in the car when they leave because things like that are more likely to be lost on the hike than to be stolen from the car.
Hm. There's a length of chain I have no idea where came from, and large butcher knife, back there, too. I had it for opening packages at Christmas and forgot to bring it back in the house. I'd better hope nobody gets stabbed to death in my neighborhood or I'm seriously in trouble.