Bird Guide:
  
While playing R4 on the course "Heaven & Hell" if
you push left right right right very quickly on 
the control pad before the countdown clock says 3
a large bird will swoop down over your car and 
lead your way down the track for as long as you 
can keep up with him. This code is a bit tricky 
because you have to be quick and I've only been 
able to get it to work in Grand Prix Mode so far. 

by PestyJoe