bluetooth phone drops when in my car. mid conversation

I'm running 10.3.2.556. However I have had about 10 different 10.3.2.x release on my classic. all of them have given me issues with bluetooth phone calls in my 328i 2012 series. (And I have updated the car system tot eh 08 version.). any ideas? I know I can't go back to 10.3.1 (very disappointed).
The problems are:
the car drops the bluetooth connection mid call.
then it randomly brings them back.
also a couple of times has completely removed the phone from pairings.