After seeing officers beat on car windows with batons, fists, guns and anything else they could find in an effort to break them, I was reminded of this tip, which can be used during a rescue effort in a car wreck or if you’re trying to get to apprehend a suspect locked inside a car.
I carried an automatic center punch that can be purchased for just a few dollars at any tool dealer. With just a push against a window it will shatter the glass. I also carry one in my personal car for emergencies. It could also be used if your car became submerged in water.