The 1M has a specific windshield washer reservoir built for the 1M fender. Removing the stock one was easy. If you do it, be very careful when unhooking the connectors for the pumps. Also note, that to remove the passenger side fender, you need to remove this first.
Draining the fluid
The first fender is off.
Reservoir and ER fender
I had been working on the car for about 3 hours at this point and decided to take a break and go to the shooting range with my girlfriend.
I was shooting 1MOA sized groups at 300 yards with my MK12
After a good trip at the range, I returned to this....
I test fitted the first 1M fender - It lined up perfectly.
Here you can see the angle of the 1M skirt vs the 135i rear end. Note how much wider the 1M is and how thin the edge is.
I discovered BMW did a part revision on the 1M front fender liners.
Old 1M liner