I guess you could also argue image commonality.
The previous M3 didn't come sedan form, so if BMW were to give this new M3 sedan it's own distinct styling, people might not associate the Sedan to the Coupe very well except for the fact that they both have the M3 name.
But by having both cars look very similar, it only adds to the 'spooled from the same gene pool' thinking. If both cars looks near enough to identical, then people will find it more easy to transfer the great reputation of the M3 Coupe to the Sedan.
Also, there's a risk with creating different styling. What happens if you're a buyer who wants the M3 Sedan (family man) but does not like sedan's styling, and actually loves the Coupe's sadistic styling? You'd have to make a compromise, either choose styling or practicality. It's a much more simpler decision if the two models look alike.
And besides, BMW and ///M think the M3 Coupe's styling really matches the image they want to create for the new M3... so why change something that doesn't need changing?
So.. you gonna buy any of that Matt ?
