You do an amount of races or you can finish cc's.
Get gold trophy in grand prixs to unlock karts and characters.
you have to unlock the different karts by racing the world cups.
you have to complete certain things to unlock stuff. this website shows you how to unlock everything, including karts. http://www.videogamesblogger.com/2008/04/18/how-to-unlock-all-mario-kart-wii-secret-characters-bikes-karts-and-more-guide.htm
By Beating cups
there is no goomba to unlock in Mario kart wii
When you hack the game.
You can't unlock Pauline in Mario Kart Wii,he isn't in that game.
Wiggler is not unlockable in Mario Kart Wii.
You can get karts by unlocking them throughout the game, and you can unlock racing clothing (if your using your Mii), You can unlock characters, by winning the 50cc, 100cc, 150cc, and also 150cc mirror cups.
Karts. It can have longer turbo boosts.
If you need to unlock her in Mario kart wii here is the answer: Win the 150cc Special Cup. If you need to unlock her in Mario Kart 7 here is the answer: Win the 150cc Mushroom Cup. Source: I beat Mario Kart Wii, and I unlock Daisy in Mario Kart 7.
ROB is not in Mario Kart Wii, he is only in Mario Kart DS.