I have a 2010 V6 and I'm putting in some 12" subs. I didn't want to replace the stock stereo so I bought this to splice into the stock harness. All I need to know is what wires are the left and right speaker wires and what is positive and negative wires.

If someone had a wiring schematic that would work too.

 

not sure on the wire colors but fyi keep that as close to the deck as you can to avoid catching and then amplifying noise.

 

If I did use an aftermarket radio is there another face plate I could buy or would a lot of the stock one just be useless?

 

a lot of the stock one? - not sure what you mean there. If you did swap out the deck you would need a kit(faceplate?) to make it fit but would not need the line out converter you bought.