If you had a software program like Carly for BMW or probably INPA you could see what may be setting the alarm off or if there are errors in the alarm system.

The most common problem on almost all of the BMW's is a faulty hood switch. Either bypass the hood switch with a jumper wire or replace it and see what happens. I think the hood switch is under $15.

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2008 4.8i Black with Tabacco. Black Y-spoke wheels and shadowline trim.