I am a supporter of FI but
lucid is right, such an engine would have to have been in their plans for the M3 all a long, there would be too much modifing needed to keep the overall package competitive, no only acceleration.
The whole point of FI is to lower the capacity not increase it, if any M cars would receive this engine then it would be the M5/6. But even them would require a new heavier gearbox because the V10 isn't what you would call a torque monster now is it.
