Can anyone tell me why this headliner wont work on a Swinger?

I know someone who bought one of these. It is not what you think. It is a cloth covered foam that you glue to your existing cardboard. You can buy the same material from a interior shop for $30.00. I use this material to fix new droopy headliners in late model cars. If you look at the item description it states cloth covered foam. They show it cut to fit your cardboard . It should be cut after it is glued on. This add is very deceiving. Beware !!