After finding I could purchase the Roadmaster Tow Guardian mounting brackets separately for $65 I decided to make my own rock guard for my tow car. The photos show the basic construction including the hitch pins at the bottom of the mounting tubing and the piano hinge in the center back. The hitch pins prevent it from coming out of the brackets if the thumb screws come loose and the piano hinge lets me fold it in half for easier storage. The guard is made from 1/2" plywood that will be painted black. I am also installing a piece of carpet to hang in the open center area to keep debris from hitting the radiator. Total cost is less than $150 and should do everything the commercial units do for over $500. Test drive coming up in April prior to 2-1/2 months in Alaska this summer. I don't expect any problems other than 1/2" plywood being too thin and flexible in the wind. It will be easy to increase it to 3/4" if necessary.