Remember the news about run away Toyota's? Well NASA seems to have figured out why. The accelerator petal uses a potentiometer (variable resistor) to control the cars speed. Turns out tin whiskers grew between the connector contacts and shorted out the potentiometer making the controller think the driver stepped on the gas. Tin whiskers have caused the failure of may things over the years and will be more of a issue since the electronics industry has gone lead free. Lead keeps tin whiskers from growing. Check out NASAs web site on tin whiskers. It really cool.