To run the 1M exhaust, I found out today there is one last piece to the puzzle that any 1 series needs.
BMW built the 1M fast and didn't design a part for just the hangars so here is some important information on that end.
This is a picture of the 1M's rear exhaust section support/hangar/bumper. This piece goes directly under the bumper cover.
If you look carefully at those pictures, you will need this item to fit a 1M quad exhaust because if you notice, I currently have three hangars. The 135i hangar is visible as its own part in silver(near the middle, holding my performance exhaust in place). In addition there are two black hangars that hold up the 1M exhaust that are this part that I mentioned that is support/hangar/bumper.