I have the Symphony (Prem Plus). The manual says that if turned off manually, the radio does not turn back on when car is restarted. Well, I've hit the mute button and turned down the volume to zero, but the radio (or media chip) always comes on when the car is started--always at mid-volume.

How do I really turn this thing off?

The only thing I've found that works is to leave it on media and make sure I've pulled my SD chip and don't have a CD inserted.

Anyone know how to turn it off so it stays off?

PS: Car has Bluetooth option, but I have no cell phone, so Bluetooth is not engaged.

 

Did you try holding the on/off button down for a few seconds?

 

I guessed this from re-reading the stereo manual and it worked.