To get this Crash Mode vehicle, just go to Extra Content in the Main Menu, and select the Madden 06 Trailer. As soon as you start the movie, the Madden Challenge Bus will be unlocked.
You cannot invite friends to ranked matches. Make sure that you make the game unranked when you create it. If you want your friend to join you for a ranked race you can send him a message and tell him the name of the lobby you're in.
