Crutchfield provided me with an adapter harness which wired up almost color-to-color with the wires coming from the new head unit. There are 2 or 3 wires on the adapter harness that are not used and the red & yellow have to be reversed. The adapter harness plugs directly into the factory radio harness. From my POV it seems very easy and the factory amp still works as before. Make sure you have the Bongiovi Circuitry engaged (push button ot top right of head unit). It makes a world of difference. Hopes this info helps you decide.