Sorry I don't have anything to add on the actual alarm. But...
People still buy alarms?
I think it's funny, that with car alarms most people just find it annoying, and are like, "would someone turn that $hi+ off" when they hear them.
I don't think car alarms really DO anything that useful. I suppose it might deter the less than savvy thief. Then again they're not gonna be able to start a modern car with the key microchip - alarm or not. And if they want something in the car, an alarm going off after breaking the window won't stop them from getting the goods.
Just my $.02. I don't think alarms are worth a darn. Then again, I live in Arkansas and car theft is like super rare.