Thanks to all for the advice about the banging panels. Some say that putting a polystyrene type of panel in place stopped it, and others say it did not. Spray foam sounds like the solution for the small gap between the panels and the roof, but using the proper amount seems tricky. I have some left over pink fiberglass insulation that I am considering using. It is a one piece metal roof so a leak is not very likely and it should stay dry. I will be using some kind of vapor barrier on the roof so interior moisture shouldn't be an issue. I still have a while before I take the trailer back to Canada and can do the insulating. Thanks again!
Dean