Comfort and Convenience
Some people like more cabin warmth after standing at a bus stop, while others arriving from a heated building prefer cooler air, because starting conditions already differ.
Safety and Driver Assistance
Before a night airport run, locating the lights, washers and heater controls while parked means those steps are already decided when the journey begins.
Multimedia and Connectivity
A child on the way to practice may want a familiar album; if cabin audio can play it, the phone need not sit in someone’s hand as a speaker.