1995 Bmw M3- E36

The microfilter is at the right rear of the ac blower near the bulkhead
or partition between the passenger compartment and the engine.
To access:
a) remove the right lower dashboard cover beneath and behind the glove box
b) remove the glove box ( first remove the ac grilles on top of box, then remove screws on the inside perimeter of box and also underneath the box, disengage and push backwards flashlight receptacle, detach connectors/plugs, and locking motor if equipped)
c) unclip and pull out air duct of footwell
d) unclip or unscrew control module holder and bring downwards
e) at the back of blower look for a long (about 7") trapezoidal plastic cover, then twist the circular lock knob counter clockwise and remove cover (or remove screws if cover is held by screws)
f) pull out and replace microfilter
g) re-install removed parts