I have struggled with the idea of covering our Solera since we bought it in 2012. We don't have access to covered storage. We use the MH year round (no snow or freeze here on the central CA coast); I have a solar cell on the roof to keep the battery charged in storage; putting a cover on and off for two to four week hiatuses between trips is too difficult, ...
I've noticed that the vertical walls (sides and back) stay pretty clean and the wax holds up quite well. The roof I don't see, and I don't want to cover the solar panel ... rain and wind seem to keep the roof pretty clear...
So, my issue has been the cab area. The roof/cabover dump dirt on the lower half of the windshield; the horizontal hood area collects dirt, leaves, bird droppings, etc.; sun strips the wax on the horizontal hood pretty quickly.
I decided that a windshield cover that extended over the hood would be great. Easy to put on and take off, and would cover where most of my exposure issue is. Searched the internet - found this available in the UK:
Protective Cab Covers. Looked perfect - but could not find a US availability.
Decided I could buy a windshield cover and add a "modified tarp" to accomplish. Came out quite good, I think - the windshield cover overlaps the tarp by about 12 to 18 inches, holding it in place nicely. Tarp is bungee'd to the mirror arms, the wheel covers, and the bumper. Goes on in two easy to handle pieces. I put the windshield cover on first - left the bottom ties to the mirror arms unconnected - folded it up onto the windshield - put the tarp on attaching it to the mirror arms - folded the windshield cover down over the tarp and attached its mirror arm ties - bungee'd the bottom of the tarp.
Thought this might be useful to others struggling with the cover question...