a toy vehicle has a body , and attached to the body is a chassis which is movably mounted thereon so as to move vertically up and down relative to the chassis . a motor is located within the vehicle and aside from propelling the vehicle forward over a support surface , the motor additionally drives a mechanism which raises and lowers the body relative to the chassis . when the body is raised relative to the chassis , the vehicle is propelled forward over the support surface by the motor ; however when the body is lowered to the chassis , the drive connection between the driving wheel of the vehicle and the support surface is severed , inhibiting forward progress of the vehicle . the vehicle performs the above noted functions in a cyclic manner , repeating one after the other .