I'm not sure I understand what you are saying. You can view the weel as a circle,the threadmill will push with a force at the point where it makes contact with it so basically the weels will rotate in the opossing direction ( making the car to move forward ). More over,because the point at which the wheel is making contact with the threadmill is moving backwards, the friction force will push the wheel forwards ( this is why F1 cars will accelerate before starting the race, because the hotter the wheel -> the bigger the friction force -> the fastest they go ).

Unless in the GIF they drag the cars by the wire, the only difference between those cars will be the friction, meaning the cars that are heavier or the cars that have the wheels made out of a different material will move faster than others.