When I needed to get into the belly and I did not want to drop the black coralast panel completely, I chose to cut a 3 sided opening. I cut the coralast material about 2 ft wide and 2 ft long leaving the uncut side towards the front of the trailer. Then swung down the flap and crawled up in and did what I needed to fix. I then took 2 inch wide wood and cut three pieces 2 ft long. I used screws to screw the wood into the uncut bottom leaving a 1 inch piece of wood exposed so the flap had a place to screw up into. Should any of the screws ever pull out, and I can't see how or why, but having the uncut flap forward the wind from driving will not pull the cut flap open. I have used this method at least 5 times on mine and other trailers without any issues. Fast, easy and cheap.
