A close relative of sitting in the shower (something I also love), sitting in the car while parked is neither about the journey nor the destination, but you being contained. The world may be your oyster, but sometimes you want to stay in your shell, OK??
P.S. if you want the deluxe version of this experience, have a little bevvie to sip while you sit with the car turned off for, say, a minimum of fifteen minutes after getting home. Sacred.