This is the guide on how you can get the access of these hidden Ninja tracks.

First of all to unlock these hidden challenges you need to compete each Extreme difficulty track with 0 faults. After compete the track with zero fault you will teleport into the remixed stages.

Now this part is a little bit hard to do, here at the end of the each Extreme difficulty track, you need to bail out just before driving across the finishing mark. Successfully deposit, you will appear in the hidden Ninja track.

Now you are in the hidden track, now go on and complete it, but dont think its easy. You can respawn at the start of the track, but exiting the level will reset the entire stage.

You have to complete the Extreme track with no faults again to access the Ninja track.