I am looking to replace my head unit in my 2010 Prius model e7022. It is the JBL with nav system. There are a lot of plugs that go into the back and I just wonder what they all are for. I'm sure one is xm radio, one is probably the microphone, etc. I have been searching all day trying to find a schematic or something to sort it all out but I haven't had any luck. Anyone help me out? Here is a photo of all the plugs themselves. I mostly wonder about this for when I have to hook up a harness for the new radio. How many of these plugs just won't end up being used?