Get Monster Truck:
Go to dinosaur level and drive back wards for a long time.
Get Monster van:
Go to swamp level and on the keyboard hit up and left or
right keys. Be careful landing!
Get Green Van:
You'll need a joystick to do this. Go to the Garden
level and on the joystick go side ways hitting the 3
and 4 buttons. Listen for a gun shot and try to do 4
Get Tydied Van:
Do the same thing that you did to get Green Van except you
go to the beach level.