While selecting the memory bank in the "SPRINT RACE" game mode, hold Select on Controller 1, then press B to erase the selected memory bank.
Press Select and Start simultaneously and you will retire from the race.
Enter the "COURSE SELECT" in either the "FREE PRACTICE" or "TIME ATTACK" game modes. Highlight either the "LONG RUN" or "FRANCE" courses, hold Select on Controller 1, then press A. This will give you two extra, hidden courses.