[mikegett]

I can't tell you what will sound good for you, but I can give a few suggestions on areas to look into. First, you stated that you changed the rear speakers. Did you do the install or was it done at a shop? Do you know if you have the factory amp? A quick peak in the trunk, on the left hand side, and behind the carpet will tell you if the system has a amp. It is a black box with monsoon printed in red letters. If you have the factory amp there is a very good chance that your new, rear speakers are not working properly. If you do have the factory amp, can you see how they are wired? You stated that a new amp was purchased. Was it for powering the rear speakers or a sub? Do you have the factory Head Unit? A aftermarket HU will most likely be wired with a set of RCA's while the factory HU will require a Line out converter.