It would be the same problem, from the factory the car is only wired to use the fronts, but they run it through an amp and seperate the speakers at that point , I personally wish the car was wired differently from the factory. I have a pioneer deck in my car and with just using the factory harness and adapter you use the two front speakers and the factory amp controls the rear 6 1/2 subs. if you want to use the rears seperate you will have to completly rewire the rear speakers.