I have a 2008 D3500 that has sat outside since new and I have always kept a cover on it.

The first three were California Car Covers made by Covercraft here in Oklahoma. I had warranty claims on all of them. Sometimes they just sent me a new cover another I had to return to be repaired. The problem has always been the stitching around the west facing windshield seams would fail.

When the last one failed I talked to Covercraft directly and once they found out I was a California Car Cover customer they were very reluctant to work with me. However they had a sale that was not matched by California Car Cover and I got one from them.

However if I had it to do over again I would probably get one from CarCovers.com. Much less expensive and they offer some covers with lifetime guarantees. I did have a cover from them that I got as a gift for my son-in-law, there was a problem with the lining and they warrantied it with out an issue and there were no problem with the replacement.