The MK4 estate used to have the facility for an accessory-fit Ford tonneau roller cover. It could be adapted to fit the Combi as it is based on the same shell BUT the Combi has a custom-made rear seat design where as the estate had a proper locking rear seat that was more "normal". You may find that the cover would not sit up to the rear seat of the Combi, or that the seat gets in the way.