A couple of weeks ago I stayed at a hotel with a large parking garage. I parked my 745i parallel so I wouldn't get dinged. The space was right next to the main driveway so cars would be passing closeby. The space was well lit and had fairly heavy traffic so I thought it would be safe. The space was also between some posts so no one was parking directly in front or back of me.

When I went to retrieve the car the following morning the red light on the rear-view mirror was flashing so I assume the alarm was set off. The car looked fine and I could see no evidence of tampering. So either someone tried to get into my car or something passing closely set it off. It made me curious about alarms.

What will and won't set off the car alarm in these cars? I know there is a motion detector. I've bumped into the car in my garage an nothing happened. When I had my 530 the alarm went off once when I parked to close to where the helicopter lands at my hospital, so there is something to detect vibration.