Comfort and Convenience
Cabin temperature is the preference people disagree about most, because warmth is felt differently depending on clothing, where someone sits and how long they have been still. A short conversation usually settles it.
Safety and Driver Assistance
It is worth locating lights, wipers, demisting and hazard controls before setting off, particularly in an unfamiliar car. Doing so while parked means one less thing to work out once passengers and traffic demand attention.
Multimedia and Connectivity
Phone battery is the usual casualty of a long trip with passengers navigating and streaming. If charging is available on board, agreeing who plugs in first avoids the scramble for power near the end.