Comfort and Convenience
At night, one person may like a dim cabin for a quiet ride home, while another prefers a little interior light to check a shopping list.
Safety and Driver Assistance
After someone else has used the car, a short pause on the driveway to find the indicator stalk and horn makes those actions familiar before the first roundabout.
Multimedia and Connectivity
If a passenger wants a quiet call with a clinic, that need is distinct from charging the handset or putting on a radio station for the rest of the trip.