68-70 Charger Sail Panels

I was browsing on Year One's website due to their 30% off thru Monday and noticed that they offered the sail panels covered and uncovered. Doesn't the headliner material cover that area? Are you supposed to have sail panel boards to make a backing for the main headliner? Why would one buy a covered sail panel board? To use as a fix in case the sail panel area is defected but not the other areas of the main headliner? This is for 68-70 Charger.

Thanks :headbang:

this is a good ?,my original ones are black colored cardboard .