my solution was going to be put 6.5" subs in the doors with my components in the kickpanels. Depending on what sub you get (I bought JL 6W0s) you can definately fit a big enought box in the door since the window doesn't take up the whole length of the door you can have a box that pretty deep. I built the kickpanels but they were all done except for vinyl and grills. But I decided to put the components back in the doors cause they were killing too much foot space and I want things to mostly appear stock. what I'll do with my 6.5" subs I don't know. But you can try my idea I'm pretty sure it would work well especially with the door subs crossed from say 50hz-150hz and the components from there up. And you would have stereo up front bass. Acutally I figured there would be enough output from the door subs that you could do without a sub in the trunk (except of course when you want to go really loud). The kickpanels really did sound good too, I miss the sound but I really had to just simplify things

Whenever i get done with my current projects, which will probly be spring or summer of next year, im going to build a custom enclosure off of my doors. I really do believe thats the best bet, all it would really take is some imagination.