Hi! I am new to the board and bought my Murano (Sunlit Copper/Blk lthr) just three weeks ago. I noticed a 'SAT' button on the radio (I got the premium sound package). I assume that stands for SAT-ellite radio. Is that part of the stereo system (and requires activation), or is that a dead button? If it is part of the radio, what do I need to do to activate it? If it is a dead button, is there some aftermarket piece of equipment I need to install to interface with the stereo? Thanks!