Got the Active EL resonated. M2C 6spd.
Installation done by Active.
Rasp is there on lift between 3 and 4K RPM
It happens with "Sound Desing" off and is worst with it on.
Rasp definitely coming from OE Box.
(Dissection not mine) someone cut the box open found the inside is lose. My guess is at certain wavelength and temp this is the culprit.
So Dinan box should arrive soon. (Thanks Mike) Will use without resonators and report back.
https://www.babybmw.net/threads/m2-c.../#post-1715542