^ You know when you make your Mii....The taller/fatter your Mii is, the higher the category..

Go to the Mii Channel and alter the height and weight of your Mii.  For instance, I'm about 6 feet tall, and a little on the skinny side, so I'm a medium class (I believe--I might be light).  Is your Mii really chunky, chunk?

OT:

My Mii is in the medium class, and I only drive in the Wild Wing, so I go back and forth between racing as Rubang and as Daisy. Every once in a while I'll toss in a Birdo to mix it up.

In a new Mario Kart, I'd want A FUCKING GOOMBA. Is that too much to ask? We have a Koopa Troopa, we had a Paratroopa (I want him back too), and now we even have Dry Bones. We've had piranha plants in Mario Golf and such, but where the hell are the Goombas?

Oh, and I WANT PAULINE. She'd flesh out the ladies section to an even 4: Pauline, Peach, Daisy, Rosalina. And she's waaaay hotter than any of them.

And I agree with Fawful.

Goomba, Paratroopa, Piranha Plant, Pauline, Fawful, WART.

Yeahhhh Koopa Troopa. Although with Sega and Nintendo's current relationship I'd much sooner expect the likes of Sonic to make an appearance.

Road creator.

That would be beyond awesome.

Lots of customation, creating gaps where you have to jump correctly, lots of shortcuts and so on.

And being able to share to others online.

Also, only 8 players online battle (and add 4P battle as option). 16 players race :D

Characters don't really matter anyways, just the kart you pick. That's why I sort of liked specials in DD, the characters you chose sorta mattered.

Samus & David Hasselhoff

The Sonic gang would be nice. Sonic would get in 1st every time, Knuckles would smash his way through, and Tails would fly over everybody.

Oh yeah. What about SNAKE!!! That would be so awesome using bombs and traps.

I say combine Wave Race and Mario Kart (not really joking about this part)...and bring along Hawkman and Cabal for good measure.