Another vote for the Saris Bones 3 rack. It works great and is very well built.
Even if you use the holder closest to the car you should be able to keep the inside pedal away from the car (I know for my car, if I put the inside pedal at a 10 o'clock or 2 o'clock position it cleared the rear of the car). Then just get a couple of small bungee cords to hold everything in place and you shouldn't have any problems with your car getting scratched.