Well Brent, that's exactly why I posted the question. To get feedback. Even like your's concerning one mode of transportation versus the other.
I figured the cover could cause some serious rubbing at most any speed, but thought someone may have tried it already.
Several years ago while traveling on a snowmobile trip across the US, I saw many trailers carrying snowmobiles with fitted covers. So I tried it once. These snowmobiles cost a lot of money and have great finishes. When I put the fitted cover on my sleds, the covers actually created "Rub" damage to the finishes of both sleds. That was when I bought a cover for my snowmobile trailer.
But it isn't as easy to just buy a cover for my trailer, so I am considering building one.
Thanks for the input....