I think I just made a discovery by accident as most are. I have been chasing a minor water problem for a while now. It has been very elusive and not very consistent but enough dampness to make me search for a leak somewhere. The floors would get damp along the walls here and there. When I removed all the carpet I found telltale signs in many spots mostly the front right behind the floor change to the cab area. Here is what I found. I was outside a couple of hours after it had rained and I leaned against the siding and water came out of the trim in the middle of wall that covers up the seam where the siding changes from flat to corrugated. I did a test with a hose and just hoseing down the whole coach as if it was raining creates the same thing. If you push in between the vertical supports water
runs out and will be a greater amount front or back depending on the pitch of the vehicle. It seems water is building up in the cavity behind and looking for a place to get out. I can see seepage through the seam and possibly the rivet holes which are a tight fit on the outside and inside but in the middle of the fastener. When things dry up I am going to clean and then run a very small bead of clear sealant along the top edge of the trim and then check for future leaks. Hope this is helpful. Lloyd