I think the rules for this category need amending. The fastest way of completing missions is to exit out right before the end (the game keeps playing in the background for a few seconds and allows you to beat the mission anyway). The only way to know whether you’ve exited out correctly is to have a clean save so you can tell whether you’ve gotten a rating on the mission or not (exited too soon).

Here are my proposed rules: if you’re gonna use the exit-out trick, you need a clean save. Otherwise, it doesn’t matter (I think a completed save that doesn’t exit out missions is slower than one that does). I think the only way to get a clean Missions slate is to delete all of your data, which does suck balls. There’s probably an AR code to do it too, and people with flashcarts can always backup their save, but to force people to run on a clean save seems a bit much.

The current WR uses a clean save, but it does not exit-out early. Why don't the rules just say "early exiting is not allowed"? (And I would use a normal Mario Kart DS card with a New 3DS. I also have the WiiUVC version, but I don't like the D-Pad.)

“Why don't the rules just say "early exiting is not allowed"?” It’s a completely legitimate technique that cuts off minutes from the run if done perfectly. If anyone is serious about running the category I don’t see why they’d prefer disallowing the technique and be slower. The only inconvenience with it is that you don’t get to see your individual Mission times unless you exit out late enough.