We have a couple of the new Ford F250's with a large box on the back... The thing is, the back door will NOT stay closed, if you go down a bumpy road or hit a large pothole boom, it's open. We've resorted to bungee strapping the door partially closed so we don't have to get out every few miles to close it. Is there anyone who has figured out how to rig these to get them to stay latched?