I read your post on the 2011 delaminating issue. A rig that is five years old stored inside or not would have hardened caulking with hairline cracks. One good rain and water gets in. If you then caulk it without letting it dry out for a week with the sun beating on it, you trap the water in and it has no where to go. You cannot blame any manufacture for it. I had a class C motor home purchased from my sister. She had it covered and hardly used it. The first thing I did was inspect the caulking which is referred to as pointing. I had to remove all the pointing and re do it. Big job, but i never got water into it. Every spring and fall I go over every inch closely. Any small hard to see hairline crack bottom or top edge of the pointing is found by pushing up, down, an in. I remove all the pointing in that area using a good sharp knife and hook and several inches beyond and then re-point it. I did this for the class C and now for my Big Horn. I had two neighbors bidding for the Class C when I went to sell it because they saw how I maintained it.