Since the E36 M3 SEDAN was based on the old E36 3-Series SEDAN, the M3 sedan was ceased to be produced when the E46 3-Series sedan came out. The E36 M3 coupe and convertible along with the M coupe and roadster were not based on the sedan so they were continued until the new E46 coupe came out. The E39 M5 is based solely on the E39 SEDAN body so when the new E60 SEDAN comes out, the current E39 M5 is done.