The strange thing is... the calipers are always on the midsection side of the wheelcase, so that black gloss detail/airhole? is on the midsection of the car, but too low compared to M car airholes. More like that chrome detail on the 7 series which is on the exact same spot.
Also that little extruded bodywork line under the logo is similar to the bodywork of a regular F30 where that line begins at roughly the same place in the front as in this picture and ends at the taillight.
Definetly not an M car. More a luxurious thing I guess.