I think it would look good. Try searching for some pics of E46 Imola interiors with Black Recaros, I think it looks awesome.
Especially if you have the black trim (you didn't specify) I don't think it will clash with extended at all.
These are best I could find. I know they have red inserts, but it can sort of give you a good idea of what the half red/black interior can look like.
It will look much better in E92 form and there is a lot more interior space around the seats in the E92 than there was in the E46