Nobody ever said by"Grand Design", merely that the factory had the option to offer it for their rally-racing promotional cars. Also, I think the fact that manual transmission info found its way into the VX parts catalog demostrates that the factory probably did install those five manuals. They had the where withall to do it best, especially the electrical part that Tom mentions.
Then how do you 'splain the convertable VX and the 4 door VX??? There's one each of those.