Daughter used to work as an adhesives specialist for Pilkingtons and is still doing odd stuff for them as a consultant. Which, while she was in the UK was useful, as she could get hold of specialist glazing products very easily and economically, but that ended when she was seconded to the USA 20-odd years ago. One of her party tricks in lectures was to get kids to hit a toughened glass screen with a mallet to try (and fail!) to break it. Then give one of them a fine pointed tool to tap it lightly, and instant shatter. She always insists we carry an automatic centre punch in the car just in case we had an accident and need to break a side window to get out.
60-ish years ago my father had an accident in his Morris Minor, which caused the toughened windscreen to shatter. After he died, my wife ran the Minor for a good few years, and we were still finding odd cubes of glass in inaccessible places.