There's months and months of fun with doing time trials. There is a leaderboard for each car/circuit combination; 12 tracks X 74 cars = 888 ! Whether you're trying to make the top 100 for each, top 10, or even No.1, it's very challenging, and great for improving technique.
Select a car, go to 'Arcade' from the menu, select a circuit and select 'time trial'.