Hint: Get bank for races:

There are five stages, and as you complete each of them you can go back and repeat the races again. You may even find that there are some races you missed. These are the ones that you want to race. When you go to these, you are not supposed to get anything for them but you can change that. To access these races, go to your garage, then your world map, and select a race. When the race begins, pause game play and restart the race. Notice that there is an option to return to world map, however after you restart it will not be there. You can now race and get bank for it.