Home made rock tamer.

Thanks Scrubby. I have been after something like that for the bottom of a gate to keep the snakes and rabbits out of our yard. They have a shorter bit that may do for the gate in mind.

I'll second the Stone Stomper, or at least a home made knockup.
A horizontal trapeze style guard is much more effective than a vertical one.
I use a Stone Stomper and not only does it keep rocks, etc. underneath where they belong, but reduces dirt buildup as well.
Have tried a Rock Tamer (Big flaps at the rear) and was amazed at the rocks I could see ejected sideways, potentially into passing traffic from either direction. It did not protect the underneath of the camper either.

The investment in a Stone Stomper is well worth while to protect your trailer or caravan from impact material. It also eliminates the "sand blasting" effect on the A frame.