Luigi EX

There are four codes that can help you get three stars. The Extremly Easy way: Use the automatic 3 star codes for those cups

The Somewhat Easy way: Use press (Select, Start, L, R, or X what ever one you chose) for bullet bill and when ever the bullet bill is about to end press the button again. And you should get a 3 star rank.

The Hard way: Use the 300cc code and race without hitting any walls and come in first every race

The really Hard way: Use Easy drifting. (where you press R to do one and as soon as you see dust or smoke or whatever it is let go and it will be the mini turbo.) Just do that like crazy and come in first on all tracks.

The Medium way: Use Press Select for final lap and just race and come in first every race.

The non action replay way: Finish in first every race and do a lot of drifting without messing up a lot.

P.S very good question

P.SS I hope that I helped you. It may sound a little bit confusing but read it over and over again if you must.