Turretless vehicle glitch
From Halopedia, the Halo wiki
This is glitch that can be done in forge in Halo 3. This glitch has several different effects on different vehicles. On the Warthog, the Prowler and Scorpion it removes the turrets. On the Wraith it removes the large section of the body where the plasma mortar is located. On both the Scorpion and the Wraith it also removes the small secondary turret. On other vehicles such as the Chopper, the Ghost, the Banshee and the Hornet when the person driving it fires, they can see the shots but no one else can and the shots do no damage.
When you perform this glitch the vehicle is still fully drivable (except the turret position). With the Warthog, Prowler, Scorpion and Wraith the smaller turret can no longer be entered as it has completely disappeared. The Wraith and Scorpion are still drivable but you cannot fire the primary weapon as it has also completely been removed from the vehicle. The glitch also makes the Mongoose unable to honk it's horn.
How to
To perform this glitch you must be in a forge game. Once in forge enter forge/monitor mode. Once in monitor mode bring up the vehicle spawn menu by pressing 'X'. When the menu is up get the party leader to start a new round. Just after 'Round Over' is heard the screen blacks out. The menu stays up for several seconds after the round over. As soon as the screen is completely black spawn the vehicle you want to it make turret-less. When the new round has started, go to the spot that you were in when the round ended. The vehicle you wanted should be in the spot you were. The vehicle will only remain in its turret-less state for that round.
If you start a new round, end the game or save the map with the turret-less vehicle and load it again in forge or a custom game the vehicle will be in its normal state. NOTE: You must spawn the vehicle immediately once the screen is totally black because if you spawn it while you can still see it won’t be turret-less and if you wait too long the menu will disappear. This glitch is relatively easy once you know how to do it. Also sometimes when you start the new round the menu disappears and you can’t spawn the vehicle.
The ability to do this glitch may or may not have something to do with the number of people in the party. It doesn't appear to work with only one person in the party because the spawn vehicle screen/menu disappears when you start the new round. Performing this glitch successfully seems to rely on connection because if your connection is too good the menu disappears, but if the connection isn't perfect or has a slight bit of lag it works.
