I screwed up and ordered a sub that is too deep to fit under my seat. I could send it back and find something shallower...but it's like $50 to ship to/from Alaska. So I want to make do.
The only place I can find to fit a box now is on the rear seat (2001 Extended Cab GMC). Is there any problem with building a box to sit on top of a seat? I'll design a path for the lap belt, and an extra hook on top to the rear car seat anchor so it won't go anywhere. But, will having it sit on top of a cushy springy seat destroy performance?