Has any one inquired about installation of a RDSport R48 motor is a e46 sedan? It might be a tight squeeze
but I think it is possible. I know Alpina did it with an e36 car. I could wait for an m3 but I understand it is not coming in sedan form.
For info, the R48 motor is the 4.4 V8 bmw engine bored out to 4.6 producing 367 hp.