> but do the cars not continually (or at least every minute or two) revalidate the presence of the key? Mine will beep for a bit if I leave the car with the ke

> but do the cars not continually (or at least every minute or two) revalidate the presence of the key? Mine will beep for a bit if I leave the car with the key. But the vehicle also works when the fob's battery is depleted (it has an RFID tag and an embedded physical key for the door). Having the car randomly shut off based on something so potentially flakey seems like a worse idea.