Just something to think about. I have done several Trav'ler installs and I always add the base plate under the satellite dish. I do this for a couple of reasons. One it spreads the weight of the dish out over a larger footprint. This probably isn't necessary, but it can't hurt. The other reason is the dish LNB has a roller that rolls on the roof when the dish is stowed. Without the base plate, this roller is rolling and bouncing (after stowing and while driving) on the rubber roof membrane. With the base plate, the roller rolls and stows on the metal baseplate. Here is a link to the base plate:
https://amazon.com/Winegard-SKA-008-...ler+base+plate