The e91 m3 conversion has been attempted quite a few times ready.
This has been talked about in this thread:
Here's a e91 wagon to m3 conversion. V10 powerplant though (I actually posted this V10 wagon in the thread above):
Here's another e91 m3 conversion. Here's Eugene-TAIWAN
's friend doing his conversion:
Did not really have any updates since last year.
For inspiration (Jon Sibals rendering):