Pros and cons of auto bike rack types I just bought a car and my girlfriend has a similar car. We don't really want to scuff up the cars with the types of racks that use pressure points on the trunk.

Neither car currently has a hitch at the moment. Neither car has a roof rack nor the ability to put one on as far as I know.

What are the pros/cons of installing hitches and using a hitch rack vs. buying one rear rack and switching it between cars as needed?

Edit:

We went to REI today and picked up the Yakima SuperJoe 2. After trying to fit it on my car, there's no way it's going to work because the inside bike will rub on the car and not sit correctly because of the pedal. We are going to go back tomorrow and grab the Yakima SuperJoe 3 because it should give us more distance from the car.
I've used a trunk rack myself and only put a little denim pocket I made over the pedal of the inner bike and haven't had any troubles with it leaving marks, even after transporting a mountain bike from Mississippi to Massachusetts using it.  Before I started using the denim pocket, I did have an occasion where I wasn't careful with the pedal and scratched the trunk lid, but that was it.