In my rig, i've got a ten inch bass tube and sub. I picked up a 400 watt amp for $75 here by me. The sub and box cost $300 total. So, $375. And, i just unstrap the tube, unplug the sub, and, TADA!!! Cargo space. Don't mount the amp to the box. Either mount it to the back of the rear seat, which I did, or, put it under the back seat, which is where the first one got fryed when it was under water, long story. If you mound the amp to the box, there is alot more to take off to get the box out of the trunk. But, do a 10 inch sub if all you want is added bass.

Tylor