My car is a 2006 M6 Coupe. And, I love her. Unlike most women in my life she actually treats me good when I take care of her. Anyways We've been battling a significantly bad little bug for quite some time now, a little pest I'm sure most of you have at least heard about - High battery drain. I'm an engineer by trade so I really attacked this one head on, hitting forums gathering info, buying meters and testing all kinds of shit. After hearing the totally clowny shit that the dealership thought was going on and what they wanted to do, I was pretty determined to at least find some clues.
There was a twist tho, in that it was very random. I hate random. He sucks, cuz he beat my ass, and it took a god awful amount of time to link the random draining to the random alarm going off - the alarm going off on its own for no reason was VERY rare, much moreso than the drain, so I rode the failboat at first and figured the environment can set it off now and then. After reading a DIS article explaining how the alarm goes off if it detects a break in any input lines combined with some test based elimination to only a few modules possible as culprits, I went ahead and pulled the bumper, took out and inspected the alarm and lo and behold:
Thats the circuit board from inside the alarm module. You can see the yellow splotches around some of the contacts. Turns out the LI/ION batteries sit right above the circuit, and leaked. I guess battery goo dripping on random electronics is bad, and will cause random shorts and other fun things! Anyways. Hope this might be useful as a possible solution path for anyone out there.