TL;DR: Speaker bad, sub good. Good place for sub? (and most likely an amp)
Im not sure if this is the right place to ask this question, but since it is the pathfinder section, it was worth a shot. I am buying a '99 pathfinder as a first car, and in the future I plan to upgrade the stereo and probably the speakers, but from what I've seen, there are only four speakers: two in the front doors and two in the rear. I don't have the upgraded Bose system, so I was wondering if there was a location already in the car that would fit a sub. Being that it is my first car, and don't know much about car audio, my first idea was to use the cubby space in the cargo area to the right. It is opposite the cubby with the jack in it, and is completely empty, so I was wondering if I could somehow put a speaker in that and maybe that would suffice, but I'm not sure, I'm a little worried it would cause the plastic to rattle bad. I was hoping to get away without doing a sub and a box that sits in the cargo area because id want to make sure I could have as much room back there hopefully. Any tips from people that did a sub install and maybe a full upgrade to audio would be nice. I also plan to upgrade the stock head unit to a cheap Sony unit with CarPlay and add a backup cam, so anyone who's done that too, maybe you could help me, and tips would be great at this point.