There is no such thing. These "cheaters" are exactly what you describe them as: Cheaters. They have hacked the game in order to have unlimited stars.
The highest award for Mario Kart is 3 Stars.
Rosalina is not in Super Mario Kart. She is in Mario Kart Wii.
The ranks for Mario Kart are: E,D,C,B,A,1 star,2 stars,&,3 stars.
you need to hack using homebrew channel. there are lots if download links on youtube. for codes go to http://www.volderbeek.freeforums.org/
Try using an Action Replay.
Do really good.
3 stars
look at youtube.com to find out
Rosalina
You have to get 3 stars in everything including the missions
By number of stars and coins
In super Mario galaxy (where Rosalina comes from) Rosalina looks after the stars (Lumas). So a luma revolves around her in Mario kart wii.