So I had the factory RES radio but it has problems, replacing it with the model with Satellite radio and bluetooth. I know I can just plug it in and it will work but does this radio have the mic built in for bluetooth or is a separate wiring harness needed? The place where I got the radio from could not tell me

 

Check to see if the radio model has a slot or jack for an external microphone. This may give an indication of whether a separate harness is required.