Bonus Cups
Successfully complete the indicated task to unlock the corresponding Cup:
Bonus characters
Successfully complete the indicated task to unlock the corresponding character:
Bonus bikes
Successfully complete the indicated task to unlock the corresponding bikes:
Bonus karts
Successfully complete the indicated task to unlock the corresponding karts:
Mirror mode
Win all 150cc Cups to unlock Mirror mode.
Expert Staff Ghosts
Defeat a Normal Staff Ghosts with a time at least seven seconds faster to unlock the Expert Staff Ghost for that course.
Alternate title screen and ending sequence
Get a "One Star" rank or better in all Cups, including those in Mirror mode to unlock an alternate title screen and ending sequence.
Special credits
Win all trophies in a class to view the credits and see a congratulations screen featuring your Mii with Mario and Peach. Win all Grand Prix Cups to get another congratulations screen featuring your Mii with all the racers.
Quick start
When the countdown starts, wait until the "2" begins to disappear, then hold 2 to get a boost at the start of the race.
When the timer to begin the race just starts, hold 1 + 2. As soon as it is about to say "Go", release both buttons and press 2 as you would normally do to start the race. If done correctly, you will get a nice boost that will usually put you in first place in the 50cc and 100cc class. Note: This may require some practice.
Quick recovery from collision
When you fall into an obstacle, press 2 precisely when you land to get a temporary boost.
Quick recovery from POW Block
You must have drifting set to manual for this trick to work. Before the third strike from a POW Block, start to drift so that your kart or bike will be in the air for the third strike. When you land, you should only spin once and maintain about the same speed.
When an opponent uses a POW Block, it will spin you out on the third POW, causing you to lose an item and speed. However, if you perform a wheelie on a bike as soon as your hear the third POW, you will spin and lose your item but maintain your speed. Additionally, if you shake the Wii-mote, it will create a force field and protect you. Also, if you are off the ground (not jumping) from something such as a ramp, you will avoid the POW Block. -From: Greg
Quick recovery on bike after being hit
While on a bike, after you are hit or run into an item, perform a wheelie to increase your speed quickly.
Use same character with more than one player
This glitch works because you are automatically placed on the character you last selected. First, make have player one choose the character desired. Next, deselect the character, and move off it. Have player two select the character. Go back one screen, then enter the character selection screen again. You should now both be on the same character. Then, have both players select the character. Note: This trick also works for three and four players.
Changing Mii driver's class
Enter the Mii Channel, and change the weight of your Mii. This will cause your Mii driver in the game to change to the corresponding weight class and give you access to the corresponding new vehicles.
Using Triple Shells as ramming weapon
After you get a Triple Shell item of any color, press 2 so that all three are spinning around you. Before you launch them, you can use them to ram other cars. It does the same damage as if you launched them at an opponent.
Defending against Blue Shells
This trick requires a Mushroom. The Blue Shell goes up and comes down. Before it hits, you will have time to use a Mushroom and avoid the shell. You should boost forward and the Blue Shell should explode behind you.
Defending against Red Shells
You can block Red Shells by equipping an item behind you. Once you have an item, hold D-pad Left or D-pad Right. Items that work are Green Shells, Red Shells, and Bananas. Do not hold Fake Item Boxes or Bob-ombs behind you.
Team drafting boost
This trick requires two or more players. While playing in VS. Team racing, draft by following a friend somewhat closely from behind. Once you get the boost, go around him or her to take the lead in front of them. Have that friend draft behind you. Keep repeating this to quickly finish a race.
Winning online
A win counts as long as points are added to your total score. For example, if you get fifth, or sometimes sixth, place in an online race, it is still considered a win. The same goes for Battle Online. You can be on the losing team, but if you scored enough coins or hits and it adds points to your score, then it can be a win.
Golden Wii Wheel icon
After using the Wii Wheel extensively in all modes, a golden Wii Wheel will appear next to your name when you go online.
Profile name stars
You can add a star next to your profile name on the results screen and the Wi-Fi races by completing all Grand Prix races with a certain rank:
One star profile name: Earn a "One Star" rank in all Grand Prix races.
Two star profile name: Earn a "Two Star" rank in all Grand Prix races.
Three star profile name: Earn a "Three Star" rank in all Grand Prix races.