KrAsH's NX
First off, I'd like to tell you a little about the history of my car and how I became a car audio enthusiast. In 1998, I bought my 92 NX1600 and did not have any mods in mind. I enjoyed the car a lot as it was. Here's a picture of my NX.

Two years later, my headunit went dead on me. I went to a local audio shop and bought an aftermarket headunit as a replacement. I bought a Panasonic CQ-DF200U. It will be changed in the future, since I am not completely satisfied with its preouts and options. Here's a picture of it in my car (sorry about the glare).

From then on, I became an addict to car audio, and I am still loving every minute of that addiction.
Last summer, I bought a Cerwin-Vega! Stealth Series 3 12 inch subwoofer and a Rockford Fosgate 250a2 amplifier to power it.
The wiring I used was 8 ga. power and ground wire, 22 ga. remote turn-on wire, 12 ga. speaker wire and, of course, RCA's. All my wiring, but the battery fuse holder and the RCA's are Phoenix Gold wires. The RCA's and the fuse holder are Lightning Audio equipment.
I made my own custom sealed box. I designed it using AutoCAD and built it with a friend's power tools. From the specs of the subs, I had to make a 1 cubic-foot enclosure. Unfortunately, I did not take pictures of the building process, but here's how it turned out.

It was built using 5/8 MDF sealed at the seams with wood glue and silicone. Screws were also used to make sure the structure was solid. Finally, since MDF is a porous wood, I used exterior wood paint on it to make sure those pores are airtight. After that, everything was covered in carpet
One of the biggest challenges I had with this install was to make sure I could still fit the car's T-Tops in the trunk with the box in it. In order to do that, I designed the box with an opening at the bottom so the T-Tops will fit. Here's how it looks when the T-Tops are inside the trunk.

I recently changed my components for Cerwin-Vega! Vega 2650 components and tweeters. They sound great! They are powered by an Orion Cobalt 702 amp. I also found time to change my Rockford Fosgate amp for another Orion Cobalt 702. This was probably one of my best moves.
After that, I realized I needed some midbass support. So, I installed two Orion XTR 6MB 6.5" Midbass Drivers in the stock rear locations. They are powered by the same amp I use for the front Vega components.