Can anybody tell me what is happening here? When I start the car, the COMAND is fine. When I drive for a bit and it warms up,if I stop and turn off car and start up again, shortly, the COMAND makes this weird noise and no longer works. If the car sits a while and gets cold, it starts again okay, until I turn it off (warmed up) again.

If the noise is coming from the COMAND unit itself (rather than the speakers), then that could be the hard drive playing up or about to die. If it’s a clicking or scraping noise then that would indicate the hard drive needs to be replaced and reformatted - probably a MB dealer fix. You could try System -> Reset but you’ll loose all your settings, music, etc, but it’s worth a shot. It obviously won’t fix a hard drive hardware error. Good luck.

Thank you for you response