I quite like the M42/M44 engine. A bit buzzy with solid mounts or with the single-mass flywheel conversion, but I always have fun in my M42 e30 (and have another M42 on a stand for my e21). I was just thinking today about Z3s for some reason, so this thread is relevant to my interests.
One thing I'll note (though I assume by now you've bought the car or not), as someone who had a roommate with a Miata and then a Jeep in college: If you're living on campus, verts are a bad idea. Out in that big parking lot in the middle of the night, they are really easy to break into via the "knife" method, and they WILL get broken into. My school is in a low-crime area and between his Miata and Jeep, I think his cars were broken into 3-4 times in a couple years, each time by cutting through the top. He ended up just putting a crappy stereo in it and leaving the doors off the Jeep eventually, just so his top wouldn't get cut anymore. YMMV.
