as mentioned, head unit replaced, factory door speakers dont sound too bad with it, much better than the stock unit sounded,.. but i am not wondering about placing two speakers in the rear cargo area,... it already has places for them, looks like its made for 4 inch speakers, and i think the factory wires are there, and should be connected to the rear door speakers.
you can also add a sub woofer to boost the audio quality of your car stereo.
i thought about that, but dont want to take up the space with a sub,... still thinking of maybe trying to find some speakers for in the roof in the 