This is a genuine BMW securing bolt, part number 51 71 8 205 286. The number stamped on the part is 51718205286; BMW's catalog files it under the short number 8205286. You will find it on our Interior Body shelf, under Other Body equipment parts.
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 6 diagrams, among them Front aggregate protective plate (51_2217) and Front aggregate protective plate (51_2291). 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.
