If you like the audio quality and just want some more thump, then Steve@******** is the guy you want to talk to. They make a great drop-in sub box that fits most medium-level subwoofers and tucks into the corner of your trunk. They also provide some excellent step-by-step instructions so it's a pretty straightforward approach for someone new to the game.
Do some searching for the ******** boxes and you'll get a bunch of information
