If we think in logically. Why does the thief need to break the car glass if they need to disalarm the car. If they must do it, then there is no point for them to break the glass because now they can open the doors if the car have been disalarm.
The main reason they do that because they wanted to take/ grab the items as quick as possible. And the most fastest way is by breaking the glass.
But if you have the glass vibration sensor, your alarm will be funtioning when they breaking the glass. And for the thief this is no good. Now depend on the theif to grab the item inside your car or just cabut away ... So now a least there is a hope for your item to be saved even the chances are 50/50 ...
However my theory here is for the thief who always breaking our car glass window and not car thief...
Just my stupid thinking here ... :p :rolleyes: