Stone Deflectors

The maker of the trailer would be a good start. Most of us make them up ourselves out of shadecloth or similar. Needs to be soft and loose so stones don't bounce. Preferably with a soft frame as well. Bungee cord is good for top and bottom

Have you tried Jayco?

Adventure offroad campers make them for their campers, I'm sure they could supply you one as a spare part?

cheers

Have you checked out

"http://www.campertrailers.org/tech_tips.htm"

they have a couple of stone deflector projects

Heckle and Jeckle

We made ours out of shade cloth in out chosen colour glued onto a frame made from square iron. I have plenty of pictures of our and other travellers different types of stone guards (upright, underslung, extended mud flaps on tow vehicle) - if you want to see any of them, let me know your email addy. They are on caravans, but principal is still the same.