If the ski is red, yellow, or gray, it's supercharged. If it has a white body with either blue or gold trim, it's NA. You can also tell quickly by seeing if the throttle body is at the front to the right of the battery which is non supercharged(NA) or if it's at the rear then it's supercharged. Or, look at the back left of the engine and you will see the supercharger which is red for 2004.