Great insight! I do get a noise too, but I would say it is more like a cycling wistling in my case. Mechanic said it could be a closed vent or stuffy AC filter, (wich I checked and were clean) no chirping for sure since noise is a on-and-off smooth but really annoying high-pitch vacuum-like noise.
Now, about that regulator, there is one on ebay posted at $100 with return policy, I'im thinking going down the list and eliminate possible scenarios, like you said, BMW tech guy believed it all started with that regulator so it may be worth give it a try.
I just turned the car on and the panel blinked like crazy and screen temperature was flashing back and forth from the set temp (74f) to 127f until I pressed the snowflake button (could be coincidence too) then it went back to uneven temperatures on each side of car. There's a used panel, from a front-crashed 750li that's compatible if needed.
You said it easy to replace the regulator, and I am decent on mechanic skills. Need to take the lower console apart perhaps? Hoping for that cheap fix I guess!
Last edited by Nicoromag; 01-24-2013 at 06:12 PM.