First time, long time...

I have a 2000 540i Sport. For several weeks I had to deal with a parasitic current draw. After she was in sleep, it was over 1A. I spent countless hours waiting for sleep mode, pulling fuses, blowing a few meters (damn alarm goes off for some fuses being pulled). I even installed a quick disconnect for my battery. Eventually my battery light displayed in the console. Turns out my alternator was the culprit. Easy fix (even though the water cooled does require a drain of the coolant). With the new alternator my sleep current draw is 40mA. Huzzah.

Hope this helps someone. But before you go buying an expensive alternator, check all the fuses (3 locations + a few under the glove) first.