Like the evel knievel motorcycle, the set of two dented stockcars were powered with flywheels that were spun up with a long plastic toothed rack. Also, a set of futuristic toy cars (each 1 foot long) powered by same plastic rack/single metal pinion flywheel. They had names like eliminator, sidewinder, etc... To make them go, you inserted the strip toothed rack down the side of the flywheel and then pulled it out as hard as you could. The wheel would whizz up to 1000's rpm. I never tried mine. I was too affraid I would never see it again.