Slow down as you approach the end of the jump after the third checkpoint. Notice 
that while you are in the air, some of the logs underneath are knocked out by an 
explosion. Instead of continuing normally, try to land on the log just before 
the fire. Back up, and tilt backwards as you fall off the rear of the log. 
Continue to rotate and do a back flip to get your wheels level again. If you hit 
your head on a beam, you have backed up or rotated too slowly. If done 
correctly, you will drop down and land on a set of planks in a small room with 
another fire. Once again, back up and flip off the end of the planks in that 
room. You will land on a pile of boards and tires at the bottom, which will 
move. Drive over them, and continue over the planks until you reach a ramp. A 
metal wall will drop down, and you can see a model of the Fibonacci Spiral.