After trying a couple different things, I had a "home" kit for an XM radio that included an antenna (about 3 inches square, with hinge to change angle). I placed it on the upper bunk (held in place by a strip of velcro). Usually I have it pointing straight up. Sometimes changing the angle a little or reorienting when parked under trees, etc. It has enough extra wire under the mattress to move it around when using the bunk, etc. It works very well and no holes. Wire under mattress to side then along top of door (under weatherstrip) to windshield, then under dash.
Something similar to this: http://amazon.com/XM-Radio-Universal...indoor+antenna
2012 Forest River Sunseeker 2300 Chevy