MY 2000 Stang sounds sad

I would start by gutting all the wires that are currently in the car, and buy two sets of Infinity reference 5x7's, and run new wires from the deck to the speakers. The Reference Infinity's sound great off deck power, give you the best bass possible without a box or amp, and sell for about $75.00 per set. While you have the door panels off you might as well add some Dynamat. I would use at least a door kit which runs about $70.00, and this will help make the speakers sound a lot better and produce more powerfull bass. I have four layers of matting in my doors, and I can shake my mirrors without my sub even turned on. All of this would cost you about $250.00, and should take you no more than 3 or 4 hours to complete. After that you can add an amp and woofer if you still want more bass.