Looking through the real front (Falcon back – This would be the base side that is attached to the Falcon wall panel) of the Volvo panel:
it is 13 1/2″ at its widest point.
5 1/2″ across the short side to the tabs
5 1/8″ across the short side without the tabs
On the real back (Falcon Front):
The front-facing rectangle is 12 13/16″ wide and 3 7/8″ tall.