Pioneer sells very good stereo gear at reasonable prices. Maybe it would be a good idea to just replace your headunit for now and see what improvements are needed later. The Pioneer KEH-P2500 CD player is a good start. You will notice the difference immediately. That should set you back around $140 or so. Wire the speakers directly to the CD player not to the car's fader. If your speakers are not "busted" you should be O.K. with this set up. Otherwise, replace as needed.
