A couple of months ago we bought a 2010 BC 3500RL. Every time we would meet a semi/large truck on 2 lane roads the sewer hose door would pop open. The plastic latch is designed to engage a small plastic 'nub' on the top of the door. There was just too much play in the latch to keep the door locked. We replaced the plastic latch with a metal latch like used on the storage compartment doors. No more problems with the door flying open.
Suggestion (if not already done on newer models): Get rid of the plastic latch.
Suggestion (if not already done on newer models): Get rid of the plastic latch.