I think saying that Z4 M being rare is a bit moot to be honest. You dont really notice its one until your less than 20 paces away from it. So as far as exclusivity goes, from a certain point of view, the Zed has it. (There's certainly not very many around my area, but a plethora of german coupe's) A zed, is what it is. BM styling does little for me though, so maybe I'm a little biased.