I towed our CRV for 60K miles without a scratch until I reached the Alaskan Highway! This is what I then learned about toad protection from rocks.
The worst device is the vertical shield mounted on the car. These hard shields can and do reflect rocks back to the motorhome and can and will cause paint and even rear radiator damage. Adding some type of damping material to the front of the shield will help reduce rock reflection. A full custom fitted bra on the car will protect it. However it must be washed every day to remove the dirt and grit that will get underneath and scrub the paint. The best device for protection is the horizontal shield type of device that extends from the motorhome to the toad. This will not however protect the toad from rocks when meeting or passing vehicles.
The toad radiator also needs protection. The horizontal shield that installs above our CRV tow bar would not protect the radiator that is below the tow bar.
The worst device on the motorhome is the large rear mud flaps installed at the rear bumper and are less than 5โ from the ground. These mud flaps will kick up rocks to the toad. Actually these arenโt mud flaps at all. They are a marketing and advertising device and not intended as a mud flap. If yours is less that 5โ from the road then remove it before the trip. The broom type of mud flap will also do little to stop rocks.
2009 Holiday Rambler 42' Scepter with ISL 400 Cummins
750 Watts Solar Morningstar MPPT 60 Controller
2014 Grand Cherokee Overland
Bob