Cool, I have the Viper Security system as described in a vehicle and it does exactly what 05 said. It is good, an excellent deterrent.
For perpetrators that laugh or balk at a little noise and lights flashing, I don't know many that can go ahead, get beyond that with fuel pump that shuts of either immediately, or within 10 second, I forget. That's another Viper feature, just not sure which time frame, have had 4 or 5 alarms in this decade.
Put the viper-supplied stickers on the car, and add as bright of a warning light as you can, not just the dash security feature. I went with with 2 types of lights, available at your security installers, and the loudest siren.
I think the jury is out on whether to get a motion sensor/eye. When I pass by a vehicle and it goes 'bleep' or 'squak', I feel like kicking in the freakin' door, but I can't - I'm a car guy.
My stocker already draws a crowd, possible mischief, for whatever reason, has always been surrounded, even by grannies, and I won't 'bleep' nobody.
Get a mini-camera too if you want the ultimate, IMO - I know I will but don't call it a Police camera.