Comfort and Convenience
Cabin temperature is a common source of quiet disagreement, because people differ in build, clothing and how long they have been sitting still. A setting one occupant finds pleasant can feel too cool to another.
Safety and Driver Assistance
A short pause before setting off to locate the hazard switch, demisting and door locks means less searching later, when passengers are talking and the road needs attention. Preparation is simplest while the car is stationary.
Multimedia and Connectivity
Passengers often board with depleted phone batteries, so a charging point matters on longer runs. Where calls can be routed through the car, hands stay free; music, separately, is usually settled by agreement among those aboard.