I have a 2008 caliber rt and I installed all the wires color to color on the stereo and the interface adapter from Walmart for my car. Everything works except audio. I looked and i have a factory amp so what do i need to do to get the speakers to work? I also am not sure about the steering wheel controls and the interface harness from walmart has to be programed as well. The stereo i put in is a phase lunear uv8 (jensen). I have printed out the harness diagrams and still no luck. Anyone able to help me?