Lots of threads and articles on covers. Some love them and others hate them. In my experience there is nothing you can do to prevent all the rub marks from wind. Also the covers are expensive and don't last as long as they should. I tried it, never again.
Scott and Liz - Southern NM
2012 Wildcat Sterling 32RL - w/level up (best option ever)
2007 Chevy 2500HD 4dr short bed Duramax w/allison
Reese Fifth Airborne air ride king pin coupler with Sidewinder