"Mario Kart" should be the new (unlockable) Mario character. It could either drive itself or be helmed by Lakitu (who is the mascot of the Mario Kart series in a way). Its standard attacks would be a variety of turns, flips, wheelies, and bumps. Its special moves could include a ramp jump with glider recovery, an engine rev/turbo boost, and a randomized item box. The Final Smash could be a Bullet Bill transformation or a blue shell.