Yes, neither are Mario Kart games. But they are spiritual siblings to the Mario Kart games and should be drafted into the Mario Kart series. Both have some great courses that would be at home in Mario Kart. Diddy Kong appears in the Mario Kart games anyway (not sure about MK8) so he is the link to Diddy Kong Racing. And in the absence of a Stunt Race FX series appearing, it may as well be aborbed into Mario Kart.

Besides, both would add some much needed freshness to the somewhat stale concept of the retro courses.

I would rather have courses from Waverace / Fzero / Excite / Star Fox even.

The only way it can work for me is make it so to play it properly you have to learn the courses or make it so that it changes so often that it never gets boring.

Maybe....

But it'll have to be DLC. I just don't think it should be included with the standard retro cups. Unless it's separated somehow.

Yes.

I'd actually love to see Stunt Race FX come back on Wii U, remade with beautiful HD graphics. I just really like how Nintendo has handled cartoon graphics in games like Super Mario 3D World, Donkey Kong Country Tropical Freeze, Mario Kart 8.

So imagine these cartoon vehicles in HD!

Wild and unlikely dream, but still fun to imagine.

It's not happening, because there must be exactly 32 racetracks, a quarter of which must be from the two most recent Mario Kart games.

I am excited for Mario Kart 9 though, because at that point they'll be out of GBA Bowser Castles and will have to include a cool track from Super Circuit. Or Mario Circuit, because they can't let anyone know that that game had interesting tracks.

EDIT: @MrWalkieTalkie Unlikely indeed, because critics will deduct points on account of the existence of Mario Kart on the system, like what Nintendo Power did when it reviewed Excitebots.

I'd like to see some kind of throwback or hat-tip to F-Zero. Maybe a track inspired by Mute City/Big Blue. Maybe as part of a DLC pack?
As soon as I saw the hovercraft kart transformation thing in the MK8 trailer, my mind immediately went to F-Zero.

Mario Kart 8 should include Rainbow Road - Psychedelic Experience from F-Zero X as one of its retro tracks.

My mind immediately went to Crash Nitro Kart, which had the exact same mechanic, complete with the wheels turning sideways.

I don't know how good of a fit any of those games' tracks would be for Mario Kart, but I am open to it. Not a bad idea. It would keep things fresh, and they only need to reuse the same tracks so many times.

What do you mean? We don't know IF there will only be 32 course!

@NintendoXtreme1 I am making a prediction based on the pattern of the last three Mario Kart games.