good one ... it help to clear street animal (human include) .... Actually car alarm is just a device to slow down theft, it can't 100% protect ..
used to have a blocking system in my previous car. Needed to switch on the lights and hit the brakes twice before you could start (kinda secret code). Seemed an original solution to be.
Most of the time if you have a desirable car or a car of any value in the UK you have to have one not only fitted as standard but also use it,people tend to forget on hot sunny days which is rare in the UK they leave the windows down a small amount but more than often you here the things go off when people go shopping.The trouble is no one goes over to see if its being stolen i guess just the noise will scare people off.
Well my neighbour has it and I hate him for that as sometimes it buzzes in the middle of the night due to winds blowing.
There was a movie about car alarms recently...it had the same name as another popular movie...I got it by accident...LOL EDIT: It was called "Noise"!! Good film!