I have beaten the easy ghosts and am no longer unlocking the fast ones. I unlocked the luigi circuit fast staff ghost but havent unlocked another since on the other levels. I’ve played all of them and beaten about half, but cannot race the fast ones.
To unlock the “fast” ones you have to beat the “easy” ones by atleast 4 or 5 seconds.
uh…I think once you beat them it unlocks another ghost…scroll and check the ghost names
type in “Mario Kart Wii guides” on google and see the fast ghost unlock times.
Check out http://www.gamefaqs.com