The Gear Vendors is the only way I'd go OD on an automatic as of right now. I'm not a fan of big floor changes and welding just for OD. Not that I'm really worried about mileage as a seasonal 3rd car for me anyway. However don't believe the hype about the "1st, 1st over..." stuff. The control box is a PITA and almost can't function that way. The best way I know of using it is the on/off switch for OD, which is wicked cool when you want that extra speed or mileage.