Darwinian selection strikes again. The cars don't start themselves when you get in, you have to push a button, so why would you think they would turn themselves off?
bhg....some cars with auto stop/start may auto stop when you park.If the car is in a garage you may not lock it and the car may remain in standby mode for enough time for you to exit the car and garage.The car may then restart.Most have auto shut off when you lock the car..or a warning of sorts.A very sad case that could be repeated.
Ryzen - why would a car spontaneously restart? There's no reason for it to be a design feature; I certainly can't think of why you would want a car to start itself from auto stop mode without you touching anything.
My wifes Nissan will stop if you are e.g. waiting on a car park for a few minutes and if any electrical load is still on e.g. the heater motor...it will restart a minute later and continue that cycle until you switch off or move off.Another annoying feature is ..when you press the start/stop button before you get out ,the engine will stop but the audio will continue until you open the door.
Ryzen - I can't understand the logic of your Nissan constantly restarting itself - that seems dangerous to me. I thought most cars left the radio on for, say, 15 mins when you turn off the ignition so that you can continue to listen before you leave the car; opening the door tells the car you've finished with it.
I recon the engine auto stops to save fuel and because theres an electrical load on the battery from say,the fan motor, the engine auto re starts to keep the battery charged.