Check out this post from Complex Rides for a set of car hacks that contains a few gems. My favorite is the pool noodle door protector for those of us parking in narrow garages. It’s especially useful when you have a kid that opens the car door like he’s a young Arthur removing a sword from the stone.
If you have an extra pair of boots laying around, collecting dust between hiking trips, toss them in the car and you’ll always have a place to put your 64 ounce Big Mama-jama.
Finally, even though we’re a little out of season for it, it’s worth remembering that hand sanitizer will de-ice your car lock. Just squirt a little on the lock, then maybe a little more and a little more, until the ice is melted by the alcohol in the sanitizer.