CART (Points to NOTHING, who waves) You’re looking right at it. Say hello.

It sounds like you're looking for a (likely for a game, animation, or short film) based on the surreal/ironic concept of a "cart ride around nothing."

Modern carts don't just use "on/off" buttons. They use a Physics Based Train Cart System involving VectorForce or LinearVelocity for movement and SpringConstraints for suspension to handle bumps.