I also built a 6x9 box like the one from msa. and it only costed me, get this, about 5 bucks to make. I just went to home depot and bought some hard board for about $5, and then used poster board to make a template, and did some cutting with my table saw. Then I used some smalll nails I had to put the box together. It looks much nicer then my old ripped up vinyl panel. I havnt installed it because I still need to get an amp for my 6x9s. I also need to cover it with fabric. I may still decide to but my 6x9s behind the seats of my car