I put in the Pioneer Z-2 Nav unit and upgraded the factory speakers to Alpine S-type components. While the sound was better, I just wasn't happy with it. Unless it was cranked up loud It sounded like all the music was coming at me from my feet. I wanted a little separation and some bass. I saw the Pioneer subwoofer from Al & Ed's and was impressed with how nicely it fit and looked in that location, but I just couldn't see spending 500 bucks for an enclosure on an $80 subwoofer. I also wanted to add rear speakers. I worked through several ideas of putting the amp and speakers in the tailgate area or behind the seat and really couldn't figure out where to put all the stuff. The solution I (really the installers at Best Buy in Brentwood) came up with was a simple box to hold everything. I have one amp running the subwoofer and one for the speakers. I added Kappa 6x9s for the rear and put everything into the box. The sound is so much better it's amazing. I don't really have the need to carry a lot of cargo and there is still room for groceries and stuff. The box can tilt forward onto the seats to get out of the way for engine work, or there are quick disconnects and it can slide out. Photos are in my gallery. BTW, the nav unit also has bluetooth and a back-up camera.