This is a genuine BMW stick-on window antenna, part number 61 12 0 412 563. The number stamped on the part is 61120412563; BMW's catalog files it under the short number 0412563. You will find it on our Electrical shelf, under Auxiliary cable. BMW has since replaced it with 2159621.
It fits every E46 body style (320i, 323i and 325i, 1999–2006), with the M52, M54 or M56 engines — and the European-market versions.
BMW draws it on 2 diagrams, among them Retrofit kit, hands-free kit, UNI (03_2781) and Retrofit kit, hands-free kit, UNI (03_2812). 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.
