This is a genuine BMW cover left painted, part number 51 21 0 018 021. The number stamped on the part is 51210018021; BMW's catalog files it under the short number 0018021. You will find it on our Interior Body shelf, under Other Body equipment parts.
It fits every E46 body style (320i, 323i, 325i, 328i and 330i, 1999–2006), with the M52 or M54 engines — and the European-market versions.
BMW draws it on 2 diagrams, among them Door swivel handle, front (from 09/00) (41_1354) and Door swivel handle, rr (from 09/00) (41_1355). It weighs about 96 g (0.2 lb).
We have not had one on the shelf yet. Request it and we will tell you when one comes off a car.
