I need improvement for car sound system. What parts should I purchase?

buy a good set of speakers and a new head unit/stereo same thing.your car is 19 yrs old and the speakers must be shot.go to eBay then car audio and take a look around the site.buy name brand equipment you get what you pay for.and now that the ipod is around head units are priced right.and if you decide to put external amplifiers the head unit has to have the right plug ins in the rear.the head unit is the brain of the hole sound system.and you will need the right Adapter plug in that hooks to your new head units wiring harness and plugs into the plugs you unplugged to remove the old head unit from.they call it plug and play,it comes with the wiring diagram follow it,this makes the job much easier.its a 9 dollar part,and can be bought at wall mart in the car audio area.if you don't plan on installing it yourself,add about 90 dollars for the install at any car audio dealer.i he rd that best buy will install the equipment for free as long as you buy from them.don't know how it works if you buy from them on line.hope this helps you out.