Ive been working on this a while as this came in mind once when i was on foundry but was hard to make as you wouldnt die when you fell of so i waited for another map to come out and sandbox was the perfect map. What i have made is a derby map (bumper cars) but with different levels 2-6 players and heres some pics below;

Mancannons spawn after 10secs into the game.

catch some air
The Map you can download from;
Halo 3 File Details
the game type can be downloaded from;
Halo 3 File Details
enjoy tell me what you think.