I know next to nothing about car audio, and what I do know I can attribute to Doug... Thanks again Doug!

The setup that I went with was kinda pricey, but it sounds incredible. I got the MBQuart RSC 216 components for in the cabin (front doors and rear deck). The installers did an awesome job getting it to sound absolutely phenomenal, and everything is hidden so it looks like I have a stock setup.

I had a custom sub box made for my trunk, so it sits next to the rear seats, between the 'shark fins' (what the installer referred to the wheel wells as). The sub is a single JL Audio 10W3. It provides the kick I like, without being muddy.

That setup might not be what you are looking for, but I love it in my car, for my choice of music (Grand Prix SE Sedan and a lot of punk/rock/classical).

Talk to the local installers - they will be able to help you more than anybody...