Bungie's minigame 'Reach Racer' discovered in Halo: Reach

It involves 2 players standing in particular spots on in ONI: Sword Base, which then triggers a two-Warthog racing game complete with waypoints.

The Achievement Hunter team have put together a handy video to teach you Halo fans how to burn rubber Warthog style, because just blasting aliens is never enough. A real Spartan needs the adrenaline of a race on a planet under invasion - yeah!