My FW sits out in the wind and elements, and has since new. I used a cover on previous FW, but what a hassle! Hard to put on, but even harder to secure in the wind. I had all kinds of extra stretch cords, over the top, using pipe insulation to protect roof edge etc. It was a nice Adco cover, held up well, but when the wind blew hard, it always needed adjustment. No more covers for me.
I do cover tires/wheels, and use an AC cover in Winter also. I think the Summer sun is much harder on our RVs, than the brutal Winters.
Jerry