I have a Dodge Ram w/the almost 4 door and a full pickup bed. I have a locking canopy (topper). My Scuba tanks stay in there year round, as I dive year round. I put them close to the cab and cover them up. My kids say the back of my pickup looks like a homeless/dead man lives back there. I've never had the canopy broken into, but I've had the cab (driver's window) broken into and they stole a nice duffel bag and nothing else of value. I live in the Pacific Northwest, and maybe if I lived in Florida or California they would rob us blind. But so far, neither me or any of my friends have suffered a break-in at our divesites in Oregon or Washington. About the dive-stickers. The main places that our trucks sit "unsupervised" is at divesites, so it's obvious we're diving. We love our stickers as it attracts other divers so that we may find buddies (difficult for the cold NW murky waters - good visibility at the Crab Hole yesterday was 6 ft!!!).