I hate the Z3. And I hate the Z4 more. I also hate the M version of the Z3 as well, partially because it looks like drunken clown-shoe designer stumbled into the BMW design room the night before the coupe design was going to be presented to board and drew all over the designs. That and my future brother-in-law makes fun of me for buying "the Porsche that you buy when you can't afford a 911." But he drives a 2000 Z3 M Coupe that he bought used with like 90k miles on it, which is what you buy when you can't afford the M5.
However, I LOVE the new Z4 coupe and Z4 M coupe!
http://www.bmwusa.com/vehicles/z4/z4coupe30si/default
http://www.bmwusa.com/Vehicles/M/Z4MCoupe/default