Listed as "modifications after issue to the troops" to be performed by field units; "Starting in December 1944, fabricate protective covers from pieces of Schuerzen and install the covers for the rear deck." - Jentz, Germany's Panther Tank, page 102.
While generally fitted to late Ausf G's at this date, they could be fitted to existing earlier models as well, although photos of this occuring might be hard to find.
This was also done on a limited basis to the turret roof, usually with sandwiched pieces of scrap armor sheet.
