I reviewed the O/M and DVD but really didn't understand all the vague instructions. My Jeep has a audio system with a built in 6 CD changer, aux jack, and many other buttons but (no nav). One button is obviously a phone so I assume you can integrate a bluetooth cellphone to be use hands free thru this audio system. Is my assumption correct? How do I go about the setup? Is any unfurnished harnesses required?