My M-sport seat’s bolster started to squeak and on closer inspection the leather was detached from the backrest panel. I could easily lift it back on the edge of the panel, but it sits loosely on the edge of the panel. According to https://z4-forum.com/forum/viewtopic.php?t=84093 the leather is held in place by stiff plastic piping and I think I can feel there’s a break in the pipe. I’ll take the seat out for more detailed examination.
Does anyone know whether the plastic pipes can be replaced?
Took the seat out today and answering my own question in case someday someone has the same problem. The edge of the leather has a plastic border sewn to it (picture below). It is just tucked into a slit along the edge of the rear panel - used a trim removal tool to tuck it back in place. Seems to stay put without any adhesive.