without knowing exactly which one, I can tell you from what I remember, there was someone who was tweaking the track.ini files to adjust the grip on various dirt tracks and playing with setups to make it all work like you see in the video.
It's fairly easy to get the left front in the air off the corner on a dirt track if it has pretty good grip... you just drop the right rear spring down really soft and raise the left rear spring a bit until the left front pops up under acceleration.
From what I messed with a few years back, it looks awesome on the videos, but its not much fun to drive.
