Okay. I'm new to the club. Just purchased a CPO 328i a little more than a month ago. All was fine until I came out the store yesterday and it wouldn't start. I got a jump and it started fine. (drove home) got up then next morning and it wouldn't start. Got it jumped and went to work. Assumed it was the battery so I went online an ordered a replacement battery to pick up onthe way home. Got a jump to leave work, picked up battery on the way home. Got home took out old battery (which still had a green light). Went to put in new battery and it is too big. BMW batter is 13.5" new battery is 15". Question - since battery is "green" does it need to be replaced. Its the original battery in a 2007. During the 2 day fiasco sometimes the lights came on, sometime the car was completely dead, sometimes the key would get stuck and it sounded like the car was continuing to try and start. weird. Any ideas on what the problem is and if it is the battery how do I find the correct size. btw - getting to an actual BMW dealership is about an hour drive each way. Please help.