I think its that the product has never left OEM and can be sold as current year product as long as it hasnt left OEM. Plus warranty doesnt start until customer takes posession. In the boat business not sure what it really hurts unless they mis rep the hours on it. Carol Shelby did this with left over Cobra parts a few years back. Took to the courts to be able to sell new Cobras as old ones using left over unused orig parts. OEM can re vin product as they see fit as long as it has never been titled.