welcome great car!
as stated directly above, the 135i rear brakes wont work on the 128i. This is a fact, so you have to get the performance rears.
If i remember, the performance rears are not yellow in color, i think they are OEM gray/black color, so at least you wouldn't have to repaint the fronts to match it!
2009 128i Coupe Crimson Red
MODS: -Injen Intake-Magnaflow Exhaust-Carbon Fiber Spoiler - Carbon Fiber Grilles - OZ Ultraleggeras - CF Mirrors