Cars with the key for speed! Burnin' Key Cars were Matchbox-type cars that had a hole in the back with a spring in it and came with a plastic key. You pushed the key in to the hole until it clicked, and then squeezed the key to release the car at high speed. Key Cars looked like your standard regular toy cars but each one was supplied with a unique plastic key with a plastic fob. You pushed the key into the back of the car until it clicked into place then you pushed a small release button on the side of the key which released a spring loaded action to send the car shooting forward! Too "posh to push" your toy cars ? Try a Key Car !