Genuine BMW part 61 13 8 367 921: Plug. The number stamped on the part is 61138367921; BMW's catalog files it under the short number 8367921. You will find it on our Electrical shelf, under Plug connection, terminal.
It fits the E36 compact (318ti, 1995–1999), with the M42 or M44 engines — and the European-market versions. It also fits the E46 touring (323i and 325i, 2000–2005), with the M52, M54 or M56 engines — and the European-market versions.
BMW draws it on 2 diagrams, among them Trunk Lid Gasket (51_4080) and Sealing cap/plug (51_9855). It weighs about 10 g (under 0.1 lb).
We have not had one on the shelf yet. Request it and we will tell you when one comes off a car.