Righty ho, just to keep this thread updated. I awoke this am and lazily tried to wake my car via the app. I wasn’t expecting much as I am booked into the SC at Glasgow on 21/12 where the SC want to try some parts to get to the root of the issue. To my shock and surprise the app connected and the car appeared in all its glory (iPhone/ Bluetooth disconnected). I let it for to sleep again and tried a few hours later, once more success!!
It’s been 100% ok since last night. Reading the M3 gone wrong thread at least one other M3 owner has had long term issues (ecall disconnected) and they have been resolved overnight.
I texted my SC diagnostic team and asked if there were any server side updates done. Tbh I don’t think they know but still want the car in on 21/12.
I’m monitoring the issue but if by Friday it’s still perfect I’m cancelling the visit.