I agree with et2 about the covers. I bought a cover about seven years ago. I used it one season, it snowed, the snow turned into ice on the roof of the coach, and we had a trip we had to take. It was a nightmare trying to get that snow, ice off top of the roof. Finally what I had to do is get a water hose and wash it down. The water would melt the snow/ice. But that was the last time that cover went on my coach. It is still in my garage all rolled up.
I just keep my coach dry washed with Solution and once a year I use a power pressure washer and I spray the whole coach with Blue Coral. Then I use soft water to rinse it off and towel dry it. The paint still looks very good. I just park it on a special drive way I made next to my house in California, plug it in to AC outlet.
I live out in the high desert of southern California and it gets hot in the summer, but I do not have a barn or special garage for the coach and it has done just fine.
I do use my coach at least once a month for short trips lately around average five hundred miles round trip. I think that is very important for the longevity of any coach or automobile.