Just to share my experience.... I was happy to find out my roof leak was not from the roof! It was actually from the under the alumium corner trim, where the vertical wall met the horizontal wall, below the over cab bed. I had to re-make and re-seal the corner but that fixed it. So these leaks can be tricky to fine. Suggest internal air pressurization test if you really want to find it quickly. I was fortunate to be alerted to my problem from another member here who had the same model class C and had the same issue.