The top 2 pieces are the front corners of the cargo area stainless surround trim, and the other 2 are the side pieces that hold down the cargo tray carpet to the floor!! There is also a straight piece that trims the front edge, that has an over 90 degree bend on it! One end of the straight piece terminates into the corner piece, and the wavy side piece terminates into the other leg! The front and corner pieces are almost hidden behind the seat, and can't been seen when the seat back is up! Geof