EDIT:
Looked at pictures of your car on the other thread.. you already have M bumper so its just direct replacement for you... and add front lip to it (look at proboner pictures for example) and call it a day.
My car doesnt have M style bumpers so thats why i have looked into it a bit. But yours already has it.
Non M looks like this and my car looks pretty much exactly like that:
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2009 35i DCT Havana brown with ivory white interior. Mods: Cobb stage 1+FMIC, Wagner EVO1 FMIC, BMS DCI, KW V3 suspension, M3 front control arms, Hardrace RTAB, Michelin Pilot Sport 4S tires.