msp/mp3 5-lug rotors can be had on a "your own risk" basis. My supplier says they will not fit, but everything I've seen from mazdas own website says that the front rotors are the same 10.79" as the P5/ES rotors. The rears are SLIGHTLY larger at 11" (a fifth of an inch which is barely noticeable). The only difference between the MSP front rotors and standard rotors are that the MSP/mp3 rotors are "ventilated". They are somewhat hollow in the middle. The rears will have a SLIGHT difference in size. Typically what you see is that when the pad sits on the rotor there is a gap between the pad and the hub and the pad and the outter rim. If this Brembo rotor is a fifth of an inch smaller all it will do is shrink up the extra buffer. Sadly, I'm not able to personally test these on the mp3/msp so I can't promise they will fit. All signs indicate that they will but it is up to you.