One of my hesitations on buying this is I wonder if it will really work - that is, will it break a window?
Same principle as spring-loaded center punch, which will reliably do the job on
non-laminated car window (which excludes windshields).
Some vehicles
do have laminated side-window, e.g. some Volvo, Lexus, Jaguar, Mercedes and, I believe, Dodge Ram pick-ups. There are others.
Houdini mentioned in
Doug Ritter's Blog.Shooting Industry Magazine's 2009 Safety Product of the Year