After discovering the incredible secret of how movie cars shift, I decided to do some more investigating into the magical world of movie cars. Like, why do cars in horror films never seem start when someone is in danger of being mauled by a psycho or a werewolf?
Thankfully, I'm right here in LA, and this place is lousy with movie industry stuff. I got pretty lucky, as I was able to find this revealing diagram in the underpants of an unconscious key grip on my lawn.
Now I get it. The sophisticated DPS (Driver Peril Sensor) assesses the driver's stress levels and uses a set of external sensors to detect lumbering, swarming, and shrieking approaches to the car, along with vibration sensors, blood detectors, and claw-on-door-handle indicators.
If these readings reach a certain minimal level, the 12V from the battery gets sent through a series of resistors, reducing the voltage to an amount just enough to crank the car without starting.
It's what's responsible for things like what's shown in this Chevy ad, and right below it, this almost identical Volkswagen ad:
It explains so much, about so many movies.