During a race or Free Roam mode, type "goldfinger". After the confirmation sound, press CTRL + Y. The game will pause. You can now move your truck freely. Use the [Cursor Keys] to move forward, hold SHIFT to drive fast and ALT to slow down. Press Q to go up and A to go down. Press PAGE UP to twist your vehicle and PAGE DOWN to twist it sideways. You can also press K to control other vehicles.