If youâ??re parking in an area where people vandalize your car, I doubt an alarm system is going to help you much. Yeah, it might prevent the theft of your car itself. But vandals and pranksters love to set off car alarms just for the hell of it. About the only thing I could suggest is parking in a different (safer) area. Or you could put a motion detecting video camera inside the car and see if you get anyone caught on film (problem is, when they see the camera, theyâ??ve got reason to bust your window).