I got my 12" Kaption sub in the box that it came with and it is very big and barley fits. I have had it behind the Passenger seat for about 3 months now and im thinking about taking it apart and building a new box out of 3/4 " MDF. Post up some pictures of what kind of box all you guys got i wanna get some good ideas. I'd perfer if i can have 2 seats in the back but if it takes up 1 seat i can live with that