Surely there is a better way to turn the radio off then turning the volume down all the way. Mute doesn't work because as soon as you activate voice anything, it unmutes. I have never had a car where you can't turn the radio/media system off.
Surely I missed something easy. My car has the comand system with navigation.

And while I'm asking questions...if I connect my iphone to the cable, it starts to play a podcast or music. How do I stop it from playing since often I just want to recharge the phone.

I would like to know as well. My problem is everytime I go into reverse and the camera comes on the radio starts playing.

I flipped through the command manual but didn't see anything about turning it off.

theres a mute button on the steering wheel and theres a ON/OFF button on the volume knob

Mute only works until I issue a voice command...and then the radio starts to play again.....it is only temporary. However, I have to experiment because it may work the same way that the volume knob does....it changes whatever is playing at the time that you turn the knob or hit the mute button.

The on/off button in the middle of the volume knob turns of Comand completely...not just the radio....so it also turns off navigation and is not useful.

So, I'm still looking for how to turn off the radio or media device and leave navigation working with voice prompt. Sadly, I've now discovered that this question has been asked since 2006 and there is no definitive answer. Hard to believe....

I select something that I don't use and is therefore not connected. When you select it, screen says "No Device Connected" and then goes back to navigation.

I never use the AUX channel in the audio setting so all I do is go into the audio settings and set it on AUX. When it's set on AUX I get no audio from any media: DVD, CD, iPod, or the Sat, regular, and HD radio. But I can still switch back and forth with the Nav and phone and still have full audio and also voice control, but just no radio/music/media audio. And when you do want the media audio back on (radio, etc.) just hit the radio button or the disc button, etc.. It'll come back on instantly.

I use the music register, radio, and media interface channels, so AUX is my open channel with nothing attached. Just pick something that you're not using.

You cannot turn the radio OFF independently to everything else. If you want all the Comand/courtesy stuff & no radio the ONLY way is just to turn it down. Of course if you let your Sirius expire then select SAT since you dont have it the radio has no sound. BUT its actually still on.
Crazy! Yep but all the Mercedes we have had for last 6 years were like that, even wife's SL500.