[AKnowles]

FWIW, I replaced my stock apmplifier and speakers. All of them. I'll be putting in a real set of subwoofers in the door this fall. Unlike many here, I'm a beleiver in replacing the stock wiring. If you just want better sound than the stock speakers then go ahead and just repalce them and use the adapter to use the stock amplifier too.

If you want the best possibke sound for your car, then consider a new amp, new wires, and new speakers. It will cost more - a lot more if you don't do it yourself as it requires removing your dash, door panels, and fishing wires through a lot of nooks and crannies (particulalry the existing rubber boot between the door and car frame) - but you will get much better sound.