Admittedly, this is nothing crazy or over the top, but it serves its purpose (quality sound for various types of music at pretty much any volume, as well as preserving as much trunk space as possible - and is still pretty clean)....IMHO this turned out pretty well for my first DIY (this setup is several years old already).

Car: 99 Integra GS sedan
HU: Pioneer Premier DEH-P730;
Front Door Speakers - Infinity Reference 6000cs;
Rear Speakers - Alpine Type R 6x9's;
Amps - Rockford Fosgate Punch 400a4 (front and rear speakers) and Rockford Fosgate Punch 250a2 (box);
One 10" Alpine Type R sub in a sealed box;

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