As the owner of several e36 m3's over the past couple of years i can tell you the following.
I love them but they are alot of time/money to maintain. I put more money into maintaining them then my e39 m5 but a long shot. Ive replaced steering racks (1,000.00) rear trailing arm bushings, water pumps, oil pan gaskets etc. on almost every one i owned. They are fantastic cars otherwise but it hits a point were you just cant do it anymore. Thats why i got my 135i, i was putting more money into maintenance then a payment for a new one. Hope this was of some help