This is a good reminder not to leave anything visible in your car on the off chance that crackheads and other criminals might think there is something of value. Also remind your guests (friends, lovers, relations) not to leave anything visible in the car. Our guests don't seem to want to believe that their car might get broken into when we stress the point. Of course, even then theives may want to just rip off components, like radios, sound systems, tires, or air bags. For those of you with the tire locky things, theives seem to know that you keep the key for that in your glove compartment.
Unless you see the crime of window busting in progress, it is not a police matter. If the vehicle has been sitting with a busted window for 5 days on the street or 45 days on private property it is a matter for DPW. Only the owner of the vehicle can file a report. If you just happen to notice freshly broken glass and a busted car window, keep walking, there is nothing for you to do.