Have you heard of the new trend in Christmas gift getting?
All you need is a crow bar, a little knowledge, and quick fingers. Before anyone knows what's happening, you can have yourself a stereo, sub woofer or anything else that would merit money from the local pawn shop!
Leave the scene as quickly as you can. You don't want to see the owner of the vehicle take the time to clean out the broken glass, call the police, (knowing it will do no good) then begin his cold, dark, hour long commute back home, with no window...or music!
From now on, we're leaving the doors unlocked! Instead of "smash and grab", it will be just grab! It's less messy and less expensive!