Comfort and Convenience
Cabin temperature is where passengers disagree most. One person's comfortable warmth is another's stuffiness, partly because clothing, metabolism and seating position all shape how a given setting actually feels to each occupant.
Safety and Driver Assistance
Setting mirrors, seat and belt before moving is worth the pause, as is knowing what the dashboard warning lamps normally look like at start-up. Preparation done stationary need not be repeated in traffic.
Multimedia and Connectivity
Calls on the move are easier when the handset stays untouched, so it is worth checking beforehand whether hands-free calling is set up. Music playback is a separate question, often handled differently.