I am planning to put this on the inner panel of the door. You want it installed in a place where you can easily grab it if your vehicle lands for some godforsaken reason. Keeping it in the glove box or some other vacant spot in the car can make it inaccessible after the chaos of a horrible accident. If your seat belt is holding you down and you can't reach your life hammer or don't know where it is, you should buckle it up. The included holder makes this easy if you have a drill and some equipment.