If your playing multiplayer there are options in the corner of the screen or if you use a wii remote in grand prix to allow you to use karts and bikes in 50cc.
Unlock the star cup and play it.
You can if you play on 50cc. You need to play on either 100cc or 150cc in order to play the Special Cup.
When you go to play Grand Prix you have the choice of 50cc, 100cc, and 150cc. Mirror Mode is something you can unlock and you play all the races backwards.
You have to beat the first championship then play the next championship to unlock volcano level in Madagascar Kartz Wii
All you have to do is play the 50cc in the Star Cup.
As many times that it takes for you to get a Star rank or higher in all of the retro cups.
When you get all star rankings in the 50cc cup, you get Baby Daisy.
You can unlock these characters: R.O.B. beat the mirror nitro cup Waluigi Beat 100cc Dry Bones Beat the 50cc nitro cup Daisy beat the 50cc retro cup Finally Shy Guy he is not only playable on download play, you must get 3 stars on every grand prix race and mission
get a gold in all cups 50cc 100cc and 150 cc
Baby Bowser is not in Mario Kart Wii, but Bowser Jr. can be unlocked by getting a one-star ranking or better on all 100cc Retro Grand Pirx Cups.
Mac or PC?
Mario, Luigi, Peach, Toad, Yoshi, Wario, DK, Bowser, Shy Guy (only Ds download play); Unlockables: Daisy ( Get 1st on every 50cc Retro cup), Dry Bones ( get 1st on every 50cc Nitro cup), Waluigi (Get 1st on every 100cc Retro cup), R.O.B. (Get 1st on every 150cc Mirror Mode (nitro or retro)) To unlock Mirror Mode: get 1st on every 150cc Retro cup)