I like your design eskibro
I've been considering a design similar to this but I don't want the speakers firing forward due to my kids.
How about firing the speakers up or backwards? This guy (see link below) built a box with (1) 8" sub that fires at the back wall of the cab. I don't doubt the box works maybe it helps by utilizing the cab corner????
Whats A Good Sub Enclosure Setup For Extended Cab Silverado's..? - Radio/Electronics/Security - SilveradoSS.com
Probox builds a single 10" upfire design that they claim works amazing!
I was thinking about putting (2) SA8's on the driver side side (either facing up or possibly backwards) and firing the port to the passenger side door. I've never seen one but I bet it would pound!!!!
Thoughts? Good discussion.