Rears use a different sized pad, disc on the m135i is bigger and thicker.
Pads removed today, they are stamped BMW and manufactured by Jurid. I spent a few hours comparing them to other pads but nothing is just right (140mmx100.1mmx19mm) a close fit is the 2011> X5m front pad.
Asked all the usual manufacturers such as brembo, pagid etc.... Nobody does one to fit as yet. The amount of dust these standard pads give off is horrible, you can see this when you remove them, lots of dust buildup in the caliper.
Pad itself is actually pretty small.