Tesla handles this quite well. You stop driving, then open the door. This puts the car in park and engages the parking brake. Other stuff happens like the do

Tesla handles this quite well. You stop driving, then open the door. This puts the car in park and engages the parking brake. Other stuff happens like the door handles present and the stereo volume turns down. Then when you close the door (if nobody is detected in the driver's seat) the car shuts off, much to the chagrin of any children sitting in the back seat listening to the music. As you walk away, the car locks automatically. The car then automatically wakes up as you approach it. Sit in, put on your seatbelt, and put it into drive to go. It's certainly VERY easy to leave an internal combustion car running (even a keyed one) if you are used to that!