I reinstalled the top corner molding using only three screws to minimize the number of holes in the membrane. I put ProFlex RV sealant under the molding where the screws were going to be inserted.
This top corner molding could have been left off altogether, but I reinstalled it to hold the rubber down while going 60 mph down the highway.
I still saw all sorts a ways for water to get behind the vertical corner molding, so I ran a 2" wide strip laterally on top of the top corner molding, covering the top of the vertical corner molding and overlapping a little.
