This really boils down to not being stupid. Leaving something valuable on your seat or even on the floor is just begging for trouble. It takes just one sketchy character to peep into your window, see something they want, and bust your window quicker than you can say "insurance claim." Stow your nice shit in a bag, under the seat, in a compartment, or the best option: Bring it with you. Replacing your goods and your window is not worth the few seconds it'll take to properly secure your tempting items.