I agree w/dutchbmw...sounds like there's a sensor failure that's causing the alarm to go off...probably not in the alarm module, but somewhere around the car. If you can settly for the fob acting as an automatic door opener and can do without the alarm feature, you may be able to connect ony some of the wires to make that function (not sure which ones, though).
<span style='color:green'>1994 325i </span>- - - 75,000 mi.
No mods - - - very happy as is!
<span style='color:green'>1995 525i </span>- - - 154,000 mi.
No squeaks or rattles... unreal!