This forum is great! Thank you so much for the advice. I've actually had to jump start my car every morning (fine the rest of the day) and the window has fixed itself. Crazy. It's like the episode of Gilligan's Island where Gilligan took a coconut to the head and was afflicted with double vision until he took another coconut to the head.
So jump-starting my car daily is sub-optimal. I"ve been extremely busy at work and my wife totalled her car last week so she's driving my daily and we're car shopping. The dealer wants $450 & the independent wants $350 to replace a $150 battery. I just can't bring myself to pay that for a 30 minute job. From what I read on the forums, the battery control module needs to reset to recognize the new battery and charge it correctly. It must work well as it appears that my current battery is the original from 2009 (33k miles).
I'm thinking that I buy the best battery (AGM 90 Ah/900CCA/size H8) I can find, the best (enthusiast grade) diagnostic/code tool specific to BMW and install myself. That way I get a new battery, a good tool and the deep, deep satisfaction of doing my own maintenance.
Currently working my way through eight pages of discussion (
https://www.m3post.com/forums/showthread.php?t=1445273&page=3). Is the Carly tool the best?
Thanks again everyone!