My 5 year old full paint PC still looks like new. It has never been indoors since leaving the factory and during oil changes at Jiffy Lube.If the diamond shield has changed color to a light brown I can't tell because my full paint in those areas is light brown.We had double pane windows in our Winnebago before getting the PC. Several of the windows were fogging up when we traded it in. So we did not get double pane in either of our two PCs. We find the white MCD shade will keep some, a lot of the cold out when pulled all the way down. I don't know if I would get double pane windows in our next motorhome, if there is a next motorhome. We don't do any winter camping after Thanksgiving.
My biggest challenge is rust and crud on the tow bar and jacks but we didn't clean those as much as we should have.