There are two ways to get promoted to the next Stage:
— Stay on top until the end of the Championship.
In order to get to the top, you need to defend as many groupmates as possible. When you defeat an opponent's car, you get a medal. You can lose your medals if the players you defeated upgrade their car and win the fight against you.
— Try Big Fight
Big Fight allows you to be instantly promoted to the next Stage of the Championship by winning a certain number of battles against all other players in your group without changing your car. You can enter Big Fight by tapping the respective button on the Stage screen.