Went out to look through some features I've never really looked at before on my 8500 or my X50 and threw it in V mode and ran around the block and comapred it to the reading my car gave me (OBC Test 9 for BMW guys).
Here are some pics of when I got back home and parked. AC on but no radio.
For the most part the X50 ran 0.3-0.5 volts higher than what my car was displaying.
I just thought it interesting. I'm not going to put too much stock in it. Maybe I'll scare them both and my hardwire won't crap out on me again like it did for a few minutes yesterday