You might watch a real car race and you told yourself that you want to be a racer when you grow up, but that won't be easy since these uys practiced for years. You would need to know a lot of things about the car and practice it again and again to be good at driving.
This is not your ordinary car race as you have to deal with not only changing gears, but overheating as well. In short, you need to change gers when you see that your car is overheating. If you won't do it then your car will simply explode.