Though this information might be helpful to someone, so here it is: This spring, after few months of neglect over the winter, battery in my M3 went completely dead. After jump start, driving around, and driving around more, it just would not keep the charge. It was dead again by next day. So, I went to Advanced Auto Parts to test the battery (if you did not know, AAP provides free battery charge and inspection, just bring it in, and those guys will do the magic). After quick inspection on one of their fancy machines, I was told that the battery is no good, and the inspection machine says it completely dead. AAP does not carry this type of batteries, and they have to be purchased from BMW dealer. After several calls to BMW dealers, and realizing that new battery will set me back $200-$300, I went back to AAP, and asked them to give it a try and place my battery on slow charge. Thanks to them, they did. Next day, I picked up my battery. The guy at AAP told me that it was charged, but only marginally, and still might need new battery. That was about a month ago. The battery is still alive and kicking, and the car starts great *knock on wood*. I would not be surprised if many of you know this, but just in case someone doesn't, hopefully this information will help.