[bwana50]

I built a short (about 18" tall) air dam on the front of my open trailer, to keep rocks kicked up by my tow vehicle from hitting the car. For the rest of it, I figure it's no more exposed to road hazards than if I was driving it, no big deal. Just cover it in the evenings when you stop.

Concur with everyone else on their "don't cover it while underway" advice.