We'd all like to gain some extra inches (fnar fnar!), but one recurring thing I'm seeing lately is people moving a vehicle 12", then pivoting it on the spot, gaining an extra few inches, before disembarking their troops.
I'm sure there was some kind of ruling against this years ago after a fiasco with a Limosinesque Ork Battlewagon which could pivot around, gaining an additional 10 inches!!