When attaching a gun/turret/cannon to a vehicle, changing direction of the gun/turret/cannon does not sync. For other players, it is always shooting straight ahead, even if it's facing behind the player who is driving and attached it. As far as I know, the original guns/turrets/cannons on their respective originating vehicles are synced fine. The shooting on all of them works as well, it's just the direction the attached ones are aimed in that causes the issue.
Also, if you attach the tank cannon to a car, it will often "attach" itself to a car window, and if you turn the tank cannon to another direction to aim it, the window will turn with it, although this bug is not synced, so others do not see it, likely to the above bug in this post. It's likely a GTA engine bug since it was never made to do this, but figured I should throw it in there just in case anyway.
