Interested in how the Halo 4 warthog will differ from the Warthogs you used in Halo games so far? If you can't wait until next year to find out, you can find out this October if you pick up a copy of Forza 4. When playing Forza 4's "Auto Vista" mode, the Halo 4 warthog along with some slick narration about its backstory by Jen Taylor (Cortona) will be an unlockable easter egg. The Warthog will only be available in Auto Vista mode and not usable in full-on competitive races, which seems fair given that running over other vehicles isn't a part of Forza's gameplay.
Source: http://haloreachbeta.com/content/halo-4-warthog-easter-egg-forza-4
