Actually in this special case the possessbar has sth to do with the vehicle (now called OverrideActionBar)
The solution is posted here: http://www.wowinterface.com/forums/s...d.php?p=269156
Running the following macro while the bar is active will return [possessbar] as true.
/run local s=SecureCmdOptionParse print(s("[extrabar]extrabar"),s("[overridebar]overridebar"),s("[possessbar]possessbar"),s("[vehicleui]vehicleui"))
How the heck is this possible if what is actually displayed is the OverrideActionBar? Well that is sth you can ask Blizzard. Neither [vehicleui] nor [overridebar] returned true.
It can be fixed by using the [possessbar,@vehicle,exists] condition. This will return true for this special case. The possessbar condition fired and the vehicle unit exists. The feast tables use the same condtion and can be used for easy testing.
The problem is: Normally if possessbar fires it will use the default main actionbar. But not in those special cases. Some wierdo decided to use the OverrideActionBar instead without telling anyone.
Currently there are 3 conditions to spawn the OverrideActionBar: [vehicleui][overridebar][possessbar,@vehicle,exists]