[stewy604]

Correct, the F85/X5M rotors are the same size as the 'blanks' that come with the MPBK.

The correct part numbers for the F85 X5M rotors are as follows:

Front - 34112284901 (left) & 34112284902 (right)
Rear - 34212284903 (left) & 34212284904 (right)

You'll also need the HEX screws that hold the rotor, fronts are 34111123072 (1 per side) and the rears are 34211161806 (2 per side). If you want to run the rear rotors, you'll need to drill the rotor hat to work with the F15 hub. Our hubs use a single retainer bolt, the F85 uses two.

I couldn't get the front hex bolts to sit flat / recessed in the rotor hat when I did my install, so I just used them for mounting the caliper and bleeding the brakes and then removed them before putting my spacers and wheels back on.