Does your coach have fiberglass interior end caps? They will move water a great distance before it becomes obvious. I am about to start hunting a leak on ours and I'm convinced it's the the where the exterior end cap meets at the first rib. I am find it wet at the trim on the top of the front windows where the fiberglass end cap ends. This happens on both ends of our coach. I feel the sealant has finaly failed in some of the seams along the roof on our coach (agrivated by a bad floor causing more body movement then it should have had).
www.airstreamdreams.com sells vulchem and some syringes to address resealing those areas. You may also need to reseal the top edges of the window frames. I would spend some time in the forum as well researching leaks. Many good posts on how to find as well as deal with various leaks that can develope.