I had the same problem some years ago with mine. We had recently had a hail storm that, I'm guessing, probably hit right on one of the pressure sensors for the alarm and damaged it. If the wind blew too hard or a neighborhood cat jumped up on the car, the alarm went off. I ended up disabling my alarm system. There are a few sensitivity levels to it, if I remember correctly, but I didn't feel like screwing with it anymore. Go check out your owner's manual. It'll tell you how to change the alarm settings.
