I have a vertical shield for my toad. It's a PT Cruiser. I towed the car to Alaska last year. Here's what I've found:
1. The windshield and front covered by the shield are protected.
2. The area below the shield - generally below the bumper is nicked from towing.
3. The car kicked up stones from towing and nicked the paint on the rear doors. This did not come from the motorhome.
4. If I had to do it again, I'd add the 3M film to the back half of the car, but it is expensive.
5. The horizontal shield that goes between the Motorhome and the car is probably better than the vertical shield.
Hope these ideas help.
W8RLM - Bob
2006 Winnebago Journey, Model 39K, 2013 Dodge Dart