No they won't, the M3 has very low offsets in the rear because of the wider fenders.
Try wheelmax.com, I believe they have replica M3 rims that have 323Ci offsets.
Or if you like the M6 wheels, there are M6 replica wheels with 323Ci offsets, 18" all around, at
www.modbargains.com.
They look HOT and I'm getting some in 19" when they become available!
**SEE BELOW**