The leather seat base cushion on my 2000 W203 C200K is loose and rocking up and down on one side of the drivers seat. I found the remains of a broken black plastic bracket (on the floor underneath) which clamps over a round metal bar under the front of the seat base cushion. Also 2 unbroken clear plastic rivets which hold this black plastic bracket in place on the metal seat base plate. If I can get a new replacement plastic seat bracket, does anyone know how the plastic rivets are held in place in the 2 holes in the metal base or what needs to be dismantled to get inside? I suppose the bodge method would be a large ty-wrap.............I'm a bit surprised the seat is held together with breakable plastic brackets anyway! Thanks in advance for any help or advice.