That the E36 4-DOOR M3 was discontinued and the M3 2 DOOR coupe continued to sell only because the new E46 3 Series Coupe didn't come out until a while after the E46 3 Series sedan (on which the E36 4-door M3 was based). The E39 is only a 4 door version. Once the new E60 5 series comes out, the current M5 is all done.