I love the e30 m3, way back in the day went to see a low mileage 88 in Olympia, loved it, told the guy I needed to sleep on it, called the next morning and it was gone. Stupid me.
The 1991 318i and 318is were a baby m3, only year with the dohc engine in the sedan or coupe, around 140 bhp was only 25 less then the 325, but 250 lbs less weight, all of it on the nose made it about as fast but much better handling. That car would have been like my Miata, never would have sold it. A van ran into the back of that car when I was standing at a red light and it was totaled.
The 4 door is so rare that there were less of these with that engine than m3.
Every once in a while one pops up and I go look at it, but they are all junk by now, no one maintained them, so it's real hard to find one. There coupe you can find at times, but I liked the sedan better, it had much more comfortable seats and the doors are a proper size