Why Have a Car Alarm?

First off, nobody pays attention to them. Everyone assumes that the alarm is going off because a cat jumped on the hood or just because.

Second, all of your neighbors will hate you.

I worked at a plant where one of the more hated managers had an expensive car with an alarm. He parked it next to one of the buildings. The building had a basement door that opened onto the parking lot. It became a game to run out, kick the side of the car and then run back in, while someone else timed how long it took for that manager to run down from his office to ensure that nothing was wrong with his precious.