As a member of the "fire extinguisher behind the seat" club, here are a few thoughts-- The things are pretty heavy and indeed can become missiles in the event of an accident. I have also seen one after it exploded in a side-impact collision-- it made an impressive mess -- it was bolted to the inside wall of a "king" cab truck. Mine is strapped onto the mounting of my full-sized truck's driver seat- behind the seat (i have a dodge- "club cab"). I used a combination of two old-style seatbelt straps and a piece of tubular climbing webbing to hold these straps and prevent them from sliding off the extinguisher. It works great, is very secure and comes out pretty quickly-- I have used it three times so far. It is kind of hard to explain here how it works. I also wanted to avoid drilling into the vehicle. Also, I use a fairly sizable extinguisher-- not the smaller/ more common ones. I'd be glad to send a diagram and look at what size I have if anyone is interrested.