Yup, the sun will damage anything you leave outside here in AZ. My coach is 20 years old and has never been stored inside. I have only owned it for 5 years. Just recently, I have acquired a house with a huge building in the back yard, so I will be parking it inside. I just re-coated the roof, and replaced the a/c unit, so I want to keep it inside as much as I can. Don't waste your money on a cover, as stated, it's hard to put on, and hard to leave when you want to easily. The wind will tear it apart like it did mine on my large 5th wheel. Never again. If you have a nice RV, do yourself a favor and at least put it in covered storage, you'll thank yourself for it.