The trim rubber seal of one of the upper windows of my 2001 Roadtrek has shrunk and started to pull away at the corners. This is not the rubber seal the holds the window in the body, but the rubber trim that slips into that and covers the edge of the window. At the top, the seam was showing a 1/2" gap. I had recently filled it, but now the rubber was lifting at the corners.
I removed about half or the rubber (it just pulls out and then slips in and is locked in place once you push it in). I refit it, especially in the corners. Now that the corners were tight, I had a 1" gap between the ends.
I have used a product called Sugru, a silicone, moldable glue. It is soft and can be molded and stays put until you pull it off. It is a very good product and has multiple uses. Here is the link, www.sugru.com
I cleaned the glass and ends of the rubber, molded a strip and smoothed it out. Here are some pictures of the repair.