I was thinking of getting one of those maybe. If you are going to be nearby the car most of the time when it maybe could get hassled, but you wouldn't hear the alarm yourself, I'd say that it's probably a very good addition to your arsenal. If you think about an alarm, it doesn't do you a lot of good if your alarm is going off and nobody's paying attention to it and you can't hear it. Again, it's just a deterrant, not a solution. The pager system is a little more of a solution since you can maybe get to your car quickly....emphasis on maybe.
The only thing it can hurt is your pocketbook.
b