Genuine BMW part 61 31 8 357 013: Switch radio communication. The number stamped on the part is 61318357013; BMW's catalog files it under the short number 8357013. You will find it on our Electrical shelf, under Switch.
It fits the E36 sedan and touring (318i, 1992–1998), with the M40 or M43 engines. It also fits the E46 sedan and touring (320i, 323i, 325i, 328i and 330i, 1999–2005), with the M52 or M54 engines — and the European-market versions.
BMW draws it on 3 diagrams, among them Single parts f official vehicles (61_0973) and Modules/switch/ch.socket, official (61_1960). It weighs about 40 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.