This is a genuine BMW rubber boot, part number 12 52 1 724 682. The number stamped on the part is 12521724682; BMW's catalog files it under the short number 1724682. You will find it on our Electrical shelf, under Other Engine Electrical System parts.
It fits every E36 body style (320i, 323i, 325i, 328i and M3, 1992–1999), with the M50, M52 or S50 engines — and the European-market versions.
BMW draws it on 2 diagrams, among them Cable harness fixings (12_0394) and Plug Terminal Eingine Wiring Harness (12_0660). It weighs about 124 g (0.3 lb).
We have not had one on the shelf yet. Request it and we will tell you when one comes off a car.