[Fathersweetness]

Got this from a friendly Volvo owner in WA.

Seat design is unlike one I have come across. There is no hook plate. What are the brackets with the black plastic hook things?
Seat came in three parts.
Am I meant to build a brace for the two thinner cushions to create a back rest? I set them up just how I think it would fit together... Any help would be appreciated.