I have a 1997 E320, excellent car and no problems. Out of the clear blue, the Alarm goes off at 3AM. Took the car in for service (a shop that services BMWs and Mercedes), $1,100 dollars and two weeks later, I pick-up the car. The alarm fails before leaving the parking lot. Starting the car activates the alarm, which makes it fun to drive in traffic. (I disconnected the alarm horn, and turning on the fog lights prevents the lights from flashing). I travel often, and the car is either at the airport or in my garage, but without a working alarm it is not the best situation. Before I take it to the dealership, and take it in the shorts, anyone got any idea whats going on.

 

Longshot but hey, whaddaya expect from keyboard technicians :

check the door switchs. they've demonstrated to be mediocre quality,
stick, fail, etc. the results can include door locks up/down while driving,
interior lights not functioning properly, panel indicators displaying at
odd times, etc. about a $10-20 part, this door switch.