I have that problem - except that I'm the only driver in my M and I'm always the one feeling the cold. H and I used to take it in turns switching the heat/air conditioning up or down. We could never compromise. Same thing at home - I usually ended up wearing a sweatshirt around the house.
I agree that the driver should be comfortable. After all the driver is ultimately responsible for everyone's safety and if the driver isn't comfortable they might not be fully concentrating on the driving.
Both 50 S14 M 16 yrs (his 3rd; my 1st)
ILYBINILWY - 24 Dec 2012 H moved out - 27 Jun 2013 Legally separated - 6 Sep 2013 Closing the door and changing the locks