Installing new rear seat back carpet…

[Silvertip]

Getting to the rear seat backs on my carpet install and the new carpet has a fiberboard piece that wasn’t on my old ones. Curious as to why it is there and whether it needs to go on the side towards the seat back or on the outside. Position is right below where the seat back ends.

[rwest]

It belongs there and will face the ground when the seat backs are down. It’s purpose is to make the seat back a shelf when folded, otherwise you would have a soft spot between seat backs and back firewall.