Instructions
Select "Time Trial" from the main menu of "Mario Kart Wii" and choose the course on which you wish to race.
Drive around the course as fast as you can. At the end of the race, choose "Save Ghost" to post a "Ghost" of your progress, an untouchable racer who will drive exactly as you did when you posted your best score.
Refine your performance to beat your own ghost. Experiment with different drivers and karts to post faster and faster times. When you post a low enough time, the Staff Ghost will be unlocked. This is a record of a particularly good run on the course by the game's developers.
Beat the Staff Ghost by seven seconds or more to unlock the Expert Staff Ghost. This is the best time achieved on the course by the Nintendo staff.
Unlock and defeat the Expert Staff Ghosts for every course. There is no goal in Time Trial after this stage; the game will register you as having completed the mode.