Mario Kart Wii Cheats - Wii
All cheats for this game by platform: Wii
Baby Daisy - 1 Star in all 50cc Wii-Cups.
Baby Luigi - Unlock 8 Expert Staff Ghost Data in Time Trials.
Birdo - Play Time Trials on 16 different courses.
Bowser Jr. - 1 Star in all 100cc Retro-Cups.
Daisy - Win 150cc Special Cup.
Diddy Kong - Complete all 50cc Cups.
Dry Bones - Win 100cc Leaf Cup.
Dry Bowser - 1 Star in all 150cc Wii-Cups.
Funky Kong - Unlock 4 Expert Staff Ghost Data in Time Trials.
King Boo - Win 50cc Star Cup.
Mii (Outfit A) - Win 100cc Special Cup.
Rosalina - Have a Super Mario Galaxy savefile and she will be unlocked after some GPs.
Toadette - Play Time Trials on all 32 different courses.
Leaf Cup - Win at least 3rd place in Banana Cup.
Lightning Cup - Win at least 3rd place in Leaf Cup.
Special Cup - Win at least 3rd place in Star Cup.
Star Cup - Win at least 3rd place in Flower Cup.
After meeting the requirements, some unlockables may require you to back out of your save file and reselect it:
Blue Falcon (small kart) - Win Mirror Lightning Cup.
Cheep Charger (small kart) - Attain at least 1 Star Rank for all 50cc Retro Grand Prix Cups.
Dragonetti (large kart) - Win 150cc Lightning Cup.
Piranha Prowler (large kart) - Win 50cc Special Cup.
Rally Romper (small kart) - Unlock 1 Expert Staff Ghost Data in Time Trials.
Royal Racer (medium kart) - Win 150cc Leaf Cup.
Turbo Blooper (medium kart) - Win 50cc Leaf Cup.
When the countdown starts wait till the 2 starts to disappear and then press and hold the 2 button. So the 2 must still be visible but disappearing.
This will give you a boost at the start of the race.
Alternate Title Screen and Ending Screen
Complete every single cup with a first place to unlock two new Title Screens and one new Ending Photo.
Get a Star by Your Name
Playing extraordinarily well in Grand Prix races can produce a Star Ranking upto 3 at the end results instead of the standard "C, B or A." Collecting these stars in all Grand Prix's adds a Star Icon next to your name in WiFi Races and on the Results Screen for your opponents to see. (Note: Say, if you get a Three star rating in every Grand Prix except one which you got a One star rating in. You would get a One starred nickname until you manage to upgrade the rank.)
One starred nickname - Get a 1-star rating in every Grand Prix.
Double starred nickname - Get a 2-star rating in every Grand Prix.
Triple starred nickname - Get a 3-star rating in every Grand Prix.
More than one person can be the same character
First, make P1 choose the character you both want to be. Then unselect the character and move off of it. Move P2 over, and select the character. Go back one screen, then go into the character select again. You should both be on the same character. Both of you select the character. Do whatever you want from there on.
Note: In the character select screen and options, whenever one of you does an animation, both of you will. Also, if P2 chooses a different kind of vehicle than P1, P1 will look strange. Don't worry, this won't actually happen in the game.
Change Mii Racer weight class
Go into the Mii Channel and change your Mii drivers weight, witch will have an in game impact causing you to change weight class and have different cars.
Quick recovery from collision
When you fall into an obstacle, press  precisely when you land. You will get a short boost to start moving again.
Quickly recovery on a motorcycle after being hit
When on a motorcycle, after you are hit or run into an item pull a wheelie to increase your speed quickly.
To get a small boost while racing, get on a long straight road. You also cannot turn while doing this trick. If done correctly, you will see several blue streaks that fly behind you. Keep driving straight and you will see a blue force field in front of you. You then will get a boost for three or four seconds. Note: This does not always work.
To score an automatic hit on anyone in a race, place a banana or fake item box immediately after you land from a DK Cannon. They will be forced to land on it.
Change Mii driver's class
Enter the Mii Channel and change the weight of your Mii. This will cause your Mii driver in Mario Kart Wii to change to the corresponding weight class and give you access to the corresponding new vehicles.
Coconut Mall: Fast time
To get the Expert Staff Ghost on the Coconut Mall time trial, use the Wild Wing medium kart. Take a right into a store on the right side after the first escalator then use a mushroom. You will see a Delfino tree person at the door.
DK Summit: Shortcut
After you shoot out of the cannon and come up to the turn, go off the jump toppers on the left. This should send you soaring through the curve and give you a good lead.
Koopa Cape: Hidden items
After making the first jump, keep going and you will notice a few Goombas walking in place. Fire a shell at one to reveal either nothing or a Super Mushroom. You can also run into one if in the status of a Mega Mushroom, Invincibility Star, or Bullet Bill.
Mushroom Gorge: Hidden items
There are some Goombas around that contain Super Mushrooms or absolutely nothing.