The Madden Challenge Bus is a super heavy crashmode vehicle exclusive to those who have a game save of Madden NFL 06.
How to Unlock Edit
PS2/Xbox: This vehicle can be unlocked if a player has a Madden NFL 2006 game save on their Memory Card. Xbox 360: This vehicle can be unlocked if a player watches the Madden NFL 2006 trailer on the game disc.
It is exactly the same model as the Mobile Diner except it features a different livery.