Championships occur extremely rare, and when they happen, it usually brings an F1 car, or a Porsche. These require you to go through usually eight (8) locations and get harder every location. These locations could have three to seven races, the last being what is called a "Grand Finale". Modes used in Championships are:
Before you can complete a Grand Finale, you need to pass the main goals of the challenges before it. They go one after the next, but are skippable using tokens. There are three different goals in each challenge. In order to get to the next challenge, you'll need to complete the main goal. If you do so, you have a choice of completing a second goal for more rewards. But there, you have to complete both that goal and the main goal in order to advance to the third challenge, which follows the same procedure.
Each race you do will costs you a tire. You will get five (5) of them at the start of a race, and replenishes every 8 hours. You can watch up to two (2) ads and earn two tires free.
If you finish all 8 Grand Finales, and still have other goals to complete, you can do so. With the blueprints update, if you earn 110 trophies, half of the blueprints are given to you for the car. The other half comes when you complete all eight of the Grand Finales.
Grand Finales are a two-lapper, no matter the location. Be ready for glitching and tons of slipping when using the F1 cars, as their light bodies and extreme power tend to find every little hole in the race to wreck you.