I've often thought that if I caught somebody actually in the act, I'd kinda like to nail their feet to the pavement and hit 'em in the face with a shovel.
Yup, you think wanton destruction is fun?
Let's teach you all about it.
EDIT: Even though the car may appear to be "abandoned", the fact it's been moved would indicate otherwise. So NOW, instead of just having to deal with the age-related deterioration that was already there, somebody will need to cover the windshield area to keep water from destroying whatever's left of the interior, rotting the carpets and floors out, etc.
So not only is the act of smashing the windshield a stupid, mindless, gutless attack on an inanimate object that can't fight back, it's become a personal attack on the person who owns the poor thing, reducing the value even further, and stealing time and money from whoever will have to deal with the consequences.