Nobody ever thinks the car alarm going off is theirs. Therein lies the problem with car alarms. They're all the same.
Now, if my car alarm yelled 'JUSTIN HARDER, YOU BIG IDIOT, SOMEONE'S TAKING YOUR SHIT,' well, that'd probably work better, now wouldn't it?
And how many times are you even parked close enough to your car to hear the alarm going off anyway? Rarely. It's not like the grocery store is surrounding a parking lot. The only thing I think when I hear the car alarm, and I bet we're on the same page here, is 'Fer cryssakes, shut it down.'
I always think it's some boob fiddling with the key chain, pressing all the wrong buttons.
Let's just get rid of the car alarm and go straight to buzzsaws. So, if a robber breaks a window to grab your I-pod, some buzzsaws drop out of the ceiling of your Hyundai and chop his arm off.
I think it's the best route.