I saw a more heavily disguised one of these in Munich in mid June while I was dropping off my car after Euro Delivery.
It was right near E.H. Harms in Garching, close to ///M headquarters and was being followed by a Sedona 135i, driving rather 'spiritedly'.
I am now wondering if it might have been an early ///M5 test mule, but it didn't have dual exhaust and wasn't very loud (135 was louder).
Oh well, missed opportunities...