Same Issue here, trying to remove the rear seat s in a159 saloon, I pulled up hard on the side edges first witch helped to break the plastic clips a bit, then pulled up on the front edge again with as much brute force as possible then eventually, they snapped and the whole bench flew straight off, next I undid the two bolts at the bottom of the upper seat and then two more nuts that you get to behind the seat through the boot near the top of the seats. i removed the plastic trims on either side of the bench by the rear door sill. I removed the headrests, but the upper comes free at the bottom but is still attached at the top somewhere, anyone know where cause now I'm stuck halfway through the job. I am trying to fit the black headliner and black parcel shelf. Any ideas would be appreciated especially if someone has done this before.