Below is the 1M parts list that the Parts Advisor at my local BMW dealership and I put together and that I had installed on my 135i to transform it into a 135iM.
You only need one of each part listed below.
Note: I hated my pop-up headlight washers. They always sprayed when I least expected them to and always left the rest of my car (hood, etc.) sudsy, so I ordered the 1M front bumper without provisions for headlight washers and had my installer remove them and fabricate me a plug for the windshield washer reservoir.
51-11-8-057-717 Trim Cover Bumper P
51-11-7-900-764 Grid, Center
51-11-8-051-613 Flap, Towing Eye, P
51-11-8-053-877 Set of Covers
51-77-8-052-517 Supporting Ledge Le
51-77-8-052-518 Supporting Ledge Ri
51-64-8-051-987 Headlight Bracket
51-64-8-051-988 Headlight Bracket
51-74-8-051-605 Air Duct, Engine Oi
51-74-8-051-606 Air Duct, Engine Oi
51-74-8-051-604 Air Duct, Bottom
51-71-8-051-591 Cover, WheelL Housi
51-71-8-051-595 Cover, WheelL Housi
51-71-8-051-596 Cover, WheelL Housi
51-71-8-051-592 Cover, WheelL Housi
51-71-8-045-553 Cover Left
51-71-8-045-554 Cover Right
41-35-8-052-625 Side Panel, Front L
41-35-8-052-626 Side Panel, Front R
51-13-8-051-601 Chrome Clip, Left
51-13-8-051-602 Chrome Clip, Right
51-77-8-053-879 Rocker Panel Trim
51-77-8-053-880 Rocker Panel Trim
51-13-8-051-817 Left Base
51-13-8-051-818 Right Base
51-75-8-051-609 Underhood shield
61-67-8-051-590 Windshield Cleaning