Slipstream 5000

During the main menu, type REFINERY.
You will get a message, lots of money
and every track will be open.

--- Secret places :
* Arizona : Go up just before the bridge
and fly thru the top left wall, just after
the bridge.
* Tokyo : Fly thru the "Software Refinery"
poster on the wall of the first tunnel. (Information from Cheat Machine)