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!
2014 C7 Corvette Stringray - Laguna Blue - NPP Exhaust - Competition Seats