I was just putting it out there, yes a rock will do, I forgot to mention that the news also said the police hate to see these vehicles stolen because of their size, and in the wrong hands, can cause major damage, much more then a Civic or a Caravan, or even a Ranger. You get a huge ass truck with tonnes of power and its not being stopped easily, a smaller vehicle however easier to stop. Vehicles are easy to steal if you know what you're doing, and a window isn't going to stop someone if they want in, the thing is that they want to make it so these vehicles can't be stolen, but thats not going to happen so to reduce the chance that they wont be stolen, put the steering wheel bar on or do something so no matter what they won't be able to start it at all, or they won't be able to move it after its started.