This is a genuine BMW side frame locking plug, part number 51 71 8 153 941. The number stamped on the part is 51718153941; BMW's catalog files it under the short number 8153941. You will find it on our Interior Body shelf, under Other Body equipment parts.
It fits the E36 coupe, convertible and compact (318i, 318ti, 323i, 325i, 328i and M3, 1992–1999), with the M42, M43, M44, M50, M52 or S50 and other engines — and the European-market versions.
BMW draws it on 2 diagrams, among them Single Components for Body-Side Frame (41_0046) and Sealing cap/plug (51_9855). BMW's catalog calls for two of these at each place it is fitted. It weighs about 214 g (0.5 lb).
We have not had one on the shelf yet. Request it and we will tell you when one comes off a car.
