BMW Repair: Sporratic 02 525i security alarm system, security alarm system, bmw logo

Question
Hello, my question is how can I fix a new problem with my car alarm.  I've owned the car since July 05'.  The car has run and worked great the whole time I've owned it.  But recently, the last couple months, the car alarm sets itself off after it is activated.  I didn't do that before.  When I would lock or scure the car, the single beep would indicate that the alarm is activated but anywhere from 10 minutes to hours after words, the alarm would go off.  I doesn't matter where I park it or anything.  I thought at first it might be indicating that my battery is going bad but I haven't noticed anything wrong with it.  I haven't brough it in to get it checked out because I'm not a car guru by any means and wanted to get an opinion first.  I'm not sure where to begin so any assistance will be appreciated.  Thanks.

Answer
Art, most common fault for this is a faulty hood switch. Next time arm the alarm by pressing the bmw logo button and press it a second time. This will disarm the interior motion sensor and the tilt sensor (It's for leaving an animal or kid in the car). If the alarm still goes off try replacing the hood switch by the driver's microfilter housing. They are very common and are cheap. Dealer should have them in stock. If the problem persists then replace the siren itself. The dealer diagnostic machine can list the reasons for alarm activation from the fault memory. Pay an hours labor for it or do as described above. I would try the hood switch first cause it's cheaper than an hours labor.
-Evan