A sample from the products for the Seat include: Seat Cover Assy, Bolt, Flange (5f9), Seat Cover Assy, Semi-double Seat Assy.
In this schematic the "Bolt, Flange (1l9)" is used most often.
This schematic depicts all components used in the Xt350h (20kw) 1988 59y Germany 2859y-332g1 Seat partslist.