The parts CD says that the //M3 3.0, 3.2 and M52 all have different airboxes and a different "suction pipe" from the airbox to the front of the car. Yet all 3 take the same size air filter and the airboxes look similar.
Anybody know if the //M parts are less restrictive to airflow? I'm sure they'd be a cheap upgrade from someone parting out an //M3.