Tatooine Shortcut:

Select a racer and make it to the 3rd stage on 
Tatooine vs. Mawhonic. About 1/3 through the
course there is a shortcut on the left side of
a straight away. If you are in 1st or closely 
following in 2nd you will make it to first place.
Even if you don't it takes a lot of time off.