stop. i can even push it now and the car is still running. you know, it's not stopping. >> reporter: like many new models, the toyota avalon has no key. instead a push button activated by a small transmitter or fob turns the car on and off. he had not read the car's lengthy manual cover to cover and had no idea that in an emergency the only way to stop the car was to hold down the ignition for three seconds. >> reporter: was it surprising? >> what was surprising was to be totally feeling like you're out of control and somewhat helpless. >> reporter: toyota says the three-second delay is a safety feature to prevent accidentally engine shutoff while driving. the company acknowledges the feature may not be well understood. five years ago 19 car models had keyless ignition systems. today that number has soared. nearly 140 have push buttons, not traditional keys, and those push buttons vary from car to car. >> everybody takes for granted that driving a car is something