Revealed at PAX by 343/Turn 10. The car will be an "Easter egg" (Dan Greenawalt) for players to unlock, but only viewable through the game's Auto VIsta mode. Part of the reason why it is not drivable due to the fact that it isn't a real vehicle, so Pirelli and Turn 10 have nothing to base the tire physics on. (Also, that shit has independent four wheel drive.) The model used is from Halo 4, provided to Turn 10 by 343 Industries.