When it comes to the Car charger, one will have to analyze the Car too.
Modern cars run some kind of "shut down routine", so after turning the engine of and pulling the key (pulling the card, leaving the car, whatever it takes) it can take up to half an hour until all electric devices (that should go offline) went offline. So, maybe the DC socket in the Car just keeps powered for another five minutes or so. My DC socket keeps powered till the battery is empty, wich is another option.