Secret:

 How to get the secret Stealth Bike ?

 To get the super secret stealth bike you need to go the Mangled
 Memories level in Rocket War and drive straight forward until you get
 near the wall.
 Bail off your rocket before you hit the wall and run clockwise around
 the arena agents the wall. As you run to the right along the wall you
 will pass several bends in the wall, at about the third bind there is
 a hidden hallway that you can walk into. You have to be on foot
 because you can't drive a rocket through the wall. You have to be
 running to the right because the opening if very small and you may
 not see it running to the left.
 Once you go down the hallway you will see a rocket inside a fenced in
 area. Get your new rocket and win the war. You must win the game on
 that rocket for it to be one of your rocket selections.
 The special thing about this rocket is that it can not be seen on the
 radar. You have to careful not to lose you rocket to another rider
 because you wont be able to see it on your radar and it will be hard
 to find.