Welcome forum members, I have recently been discussing this subject with another forum member via PM.
It may be of interest to others so I just thought i'd start a thread to see if it helps.
A fellow forum member was advised by BMW parts department that the M3 style side mouldings probably wouldn't fit a standard E36 that comes with the slim mouldings.
My car came with the slim ones and I successfully replaced them for the M style ones.
Ordinarily you would expect BMW to know everything about the cars that they manufacture and sell. This is never the case... BMW were absolutely no use to myself when I carried out my transplant.
This is because when they do a search they will only view parts that fit your vehicle. They are not interested in helping you fit parts from other models.
I am going to post a couple of pictures that will help show that these items do fit.
Big thanks to RYM for allowing me to copy his post