I have improved the factory system. I wanted a completely stealth system. Therefore, I kept my stock headunit and improved the sound around that. It isn't the loudest system, but the quality is amazing and it will hurt my ears
I have added Infinity Kappa Speakers-6x9 front, 6 1/2 round rear. The front require major work on both the truck and the speaker. The rear bolted right in.
I've also installed a custom box under the rear seat. The box is a little different in design since the Infinity subwoofers fire into the box and out a port on the front. It was purchased off ebay and was made by "The Woodshop" in Texas. I have seen this same box sold in our local car audio stores.
This photo shows the subwoofers mounted in the box. I hinged the box on the front so I can access the speakers a little easier. For power, I have installed an Autotek 5750 5-channel amp. It's not a powerhouse, but it really drives everything very smoothly. So far, absolutely no problems.
The subwoofers fire into the box and exits at a square port which is center of the cupholder.