El Cajon Track- To access El Cajon hold Up on the controller and press the L button and the R button at the same time. You should hear an air wrench if it worked. To play the El Cajon track select El Paso and hold the Z button and press the gas button.

Flagstaff Track- When you're at the track selection screen hold Left on the controller and press the L button to access the hidden Flagstaff track. You should hear a sound of an air wrench if it worked. To actually play the Flagstaff track select Mojave and hold the Z button and press the gas button.

Guadalupe Track- To access Guadalupe hold Down on the controller and press the R button. To play the Guadalupe track select Vegas and Hold the Z button and press the gas button.

Monster Trucks- To get monster trucks, press the respective button once at the car select screen. Press again to show the default truck:
Punisher: Down-C
4x4 Monster: Up-C
Thunderbolt: Left-C
The Crusher: Right-C