I need to replace the rear roof panel due to a leak on the roadside corner and a leak where the top center seam meets the rear panel. When I pulled off the abs cap I noticed that other than some black caulking in each corner there is nothing where the metal trim meets the aluminum roof and no caulk in the channel where the edge of the abs fits into the metal trim. What advice do you have when I put this back? Should I put some double sided eterna tape on the aluminum roof edge and stick the trim to it? What about sealing the channel that the abs panel fits in. Also, where can I get a new gasket for the roof?