works very well since it's tempered glass....you're thinking about the laminate glass on the windshield. This is for the safety glass on the sides and rear. Ever see a broken car window? you just have to break the surface tension at one point and whole thing shatters, I'm sure there are vids on the internet of it.
I'm away from my family with my gf's dad, step mom and little sisters (7 and 9) in florida. My best gift was that her dad paid for us to fly down here

and some little things, like a zappy laser gun keychain. (like fifty cents, but it's cool).