I am getting ready to install a nav update, and the supplied instructions refer to a "Audio Power Button." I can't find anything in the car labeled or operative for that, nor is there a reference to it in any owner's manuals. Come to think of it, I can't recall ever being in the car when audio wasn't on. What am I missing?

 

It is at the left edge of the CD slot, just to the right of the Volume button. It is not marked, nor identified in the user documentation. I thought it was associated with the CD player, so never tried it.