The only auxillary input for this receiver requires the KS-U57 line input adapter, which plugs into the CD Changer jack. You then select LINE IN (press the CD button until the screen says LINE IN), and adjust the volume to your preference.
I put a Motorola bluetooth wireless kit in my car, and just used the Motorola speaker and microphone. The kit has an ATT wire that will mute the stereo when the phone rings, and it works quite well with no feedback or distortion. You might want to look into doing the same sort of thing as it will be a lot easier and a lot less chance for feedback.
Link to your JVC's manual:
http://books.jvcservice.com/download/641045531/34084.pdf
Devin