Crewmax rear seat delete for spare 37s?

My rear seats are folded up I'd say 99% of the time - I don't remember the last time I had someone sitting in the back seat. Usually, my dogs or gear to go wheelin are back there. I carry a full size 37" spare in the bed and it uses up valuable real estate. The rear seats from the window are 20" of useable space.



Has anyone removed their back seats and created some sort of mount that utilizes the rear seat mounting holes? Or know of a product that does something similar?

 

To run a full size sub and tool box. I built a platform, used MDF and topped with a poly sheet.