Just picked this up and I am looking to upgrade the tune making ability. It has the "upgraded" stock system with 6 speakers and a sub. It sounds pretty hollow which makes me think the Sub might not be working properly. Bottom line is I would prefer to keep the stock head unit so that I don't lose the backseat controls. It has a tape deck built into the console and I have been told that you can take that out and use the connection there for an Aux input. Anyway thinking I would like to replace the speakers and sub, maybe throw a small amp to help push them. My goal is to have it sound good, but not trying to shake the driver next to me. ANy thoughts?