I have a Crimeguard alarm, it's saved my ass twice. One time, my car was parked on the street in front of the townhouse I was living in at the time. I was asleep, a couple of my roommates were still awake and they heard the alarm go off. They looked outside to see a car zoom out of there w/ headlights off. So they run up and get me and tell me someone was just trying to break into my car. Took a baseball bat outside with me to check on the car, but no damage done. Similar thing happened again a few months later at the same townhouse, cept the car was in the driveway on the side of the house. Again, no damage.
Only one false alarm -- during the biggest thunderstorm I can remember in recent years. HUGE, LOUD, LONG thunder boom set off the alarm. Well, it does go off when I park it outside, under the runway at the airport. I've learned to leave it in valte mode when I park there, the lot has a barbed wire fence around it and 24 hour security.
It's a dual stage shock sensor, the first stage is a little too sensitive. If someone slams their door next to my car it'll let off a few beeps. I'm pretty darn happy with the thing. Cost me $250 installed, 4 years ago, 3 weeks after I bought the car.
