Thanks for the tip. I will check it our tomorrow. As far as I remember, I think I have the grille looking (with slots) motion sensor.
Somebody suggested me to check out the alarm switch under the hood.
I will look into that as well.
Originally Posted by BMWJNKY
Take a look at the square in the middle of your headliner. This is part of the interior sensor for the alarm, its about 4"x4" and the same color as the headliner. If the square is "solid" looking, as in no plastic grille with slats in it you need to get an updated interior sensor. The early interior sensors have a known issue with setting off the alarm for no real reason.