When you buy a BMW oil filter for the MZ3 (and maybe 2.3/2.8 also) you get a package with filter and four washers. The two rubber washers are real easy to figure out. The big one goes on under the oil filter cap and the tiny one goes on the end of the bolt/spindle.
Now I've got two metal washers left over. The larger one is brass and about 15 mm ID. The smaller one is steel and about 10mm ID. I assume these are for the drain plug (1.9/2.3/2.8/3.2 use different plugs?). I use a Topsider to suck the oil out and therefore haven't pulled the drain plug yet.
Is this correct or am I missing something.