When you are about 50% through the lap, you will see pine trees to the left and a hill straight ahead. Instead of going up the hill, turn left and go through the trees to enter a cave. When you get out of the cave, do not turn left on the road. Keep driving straight and you will be in another shortcut -- make sure you do not fall in the lake, or you will restart on the road.
At the end of the lap, you will enter the city. Before you go past the front lift where the rocks are, turn directly left and you will be on a shortcut. Note: It only appears at certain times.
Aspen Winter track
During the race you will go around a bend, and to the left you will see a frozen lake. Turn left, go across it, then go over the snow hill to save about ten seconds of time.
Canada track
At the first mill, the road will be off to the left in a bridge. Keep right, hit the ramp, and go through the windmill to land back on the road.
At the second mill, there will be boxes stacked to the left. Go behind them and go up the ramp. Be sure you land on the logs after it -- if you do not, you will fall in water and restart on the road.
Hollywood track
After going under the T-Rex's legs in the road, keep straight, hit the jump, then turn left and you will be back on course. Note: You could miss the jump and fall in water.
Nevada track
On the first turn you will see a dirt road. Take it you will not have to go around the bend.