If your vehicle sits off the ground, has a plastic tank, a locking gas tank lid won't help you. If they want it bad enough they will drill it and collect it in a pan. That's what happened to me. They must have been upset to only get a couple of gallons cuz the dented my truck where the gas door is at. Upper part of Bull Shoals just south of Taneyville Mo. Parked at a campground that just closed for the season. Thinking next time I come down, to park at/with outfitter were there is a watchfull eye present.