The Shake 'n Go Racers Kevin Harvick is a completely new licensed car. The basic play pattern consists of shaking the car, which activates a motion switch.  The motion switch relays the amount of shaking to the internal IC, which in turn plays sound effects that sound like an engine revving up.  As the child shakes the car more, the engine revs higher and higher until it is fully charged up.   When the child places the car on the ground, there is switch in the front axle that when triggered, engages the motor and the car takes off with the IC playing the appropriate sound effects.  There is a direct correlation between the amount of shaking and the length it runs.