This is a genuine BMW knurled head nut, part number 41 12 8 186 428. The number stamped on the part is 41128186428; BMW's catalog files it under the short number 8186428. You will find it on our Exterior Body shelf, under Other Bodywork parts.
It fits the E36 touring (316i, 318i, 318tds, 320i, 323i, 325tds and 328i, 1994–1997), with the M41, M43, M51 or M52 engines.
BMW draws it on the Trunk Battery Cover (51_2382) diagram. BMW's catalog calls for two of these at each place it is fitted. It weighs about 4 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.
