With Mario Kart 8 Deluxe's Booster Course Pass now fully available, many fans are turning their attention to the future of the series and a potential Mario Kart 9. Given the overwhelming success of Mario Kart 8 Deluxe on the Switch, it seems likely that Nintendo is gearing up to have a sequel ready when the successor to the Switch launches. While it might seem like a massive undertaking for a Mario Kart 9 to top all the content packed into Mario Kart 8 Deluxe, the game could set a new standard for the franchise by incorporating a core element from one forgotten Nintendo franchise.