Has anybody elso noticed a faint twittering noise at low speeds once the engine has warmed up properly? Never heard it while driving at higher speeds, but it's possible that the road noises are covering it. Sometimes I can hear it even when stationary and the engine has been switched off, so it's not coming from the engine itself or the aircon. I was wondering if it has something to do with the new thermal management system introduced in the new M270 engine?