No one is going to make the car if they don't know what the juice it's for, that's the whole problem with keeping it secret. I don't doubt that it's better than "oh it would just be cool to have it in" but like Filipe said, "How can I get interested if I have no idea what it is for?" No one is just going to make the car out of the thin air without knowing what it's for. Unless they have a lot of time on their hands.