Earn the indicated number of points in Grand Prix mode to be rewarded with the corresponding number of stars.

1 star: Earn 54 or 55 points (two 1st and two 2nd place finishes or three 1st and one 3rd place finish)
2 stars: Earn 57 points (three 1st place finishes and one 2nd place finish)
3 stars: Earn 60 points (four 1st place finishes)