Violence is not an option, you have to much to risk and it doesnt solve anything!

You must work on the evidence. A camera inside your car is legal. You can have an argument with a co wworker at the office it happenes a lot but when it comes to damaging your own property then its a problem. Maybe you can think of parking your car near a security camera thats already working.

Take this up to your boss, share your thoughts tell him you are having problems maybe he will think of a solution.