Originally Posted by THE TECH
Since they mfg the caliper themselves, they can use the same physical caliper but mfg it with different piston sizes.
Yes, but that means you can not move the front caliper to the back as the other poster mentioned earlier up. You need a rear-specific caliper as the existing one is a front-specific caliper.
I really hope they are using a M3-specific caliper application as opposed to using a universal sized piston caliper with adapters to fit the M3. The brake proportioning will be way off.