just bought 2009 a3 sportback with chorus system(didn't know it was very basic, should have researched first, but would still have got the car anyway). Found out on the forum that some don't have rear speakers, confirmed this with a torch. I was hoping to upgrade the system by simply changing the chorus to concert/symphony, but now I need speakers and wiring as well. does any one know all the parts I will need to get sound to the rear. I have seen concert's on e-bay for 40-100, but what else will I need. I don't want to spend too much, 200ish.Is that wishful thinking, possible, or will I just get use to it. my old a3 had the bose system, didn't realize how good it was until now. Any advice will be greatly appreciated.