There were three levels of engines for the Z3 M Coupe in its production run from 1998 to 2002. The most powerful one, 3.2-litre S54 engine from the E46 M3, was produced from 2001-2002. It provided 325 hp (242 kW) in European form and 315 hp (235 kW) in North American form. Only less than 1,200 were produced worldwide. Making it most likely the rarest of the modern BMW automobiles. (wikipedia.com & shinyside.net)
(Photos from petrolicious.com)
(Photos from shinyside.net & autowp.ru)