2nd Gen Gun Compartment

Moderators, apologies if this is in the wrong place. I remember seeing on here or maybe another site that someone had made a gun compartment in the truck for a long gun. If I remeber correctly they made modifications to the rear seat area. Are there any plans or step by step I can rip?
I do not have a topper, bed cover or tool box. This is why I am asking, when me and the family go shooting I would like a good place to keep the weapons out of view. My search foo turned up nothing that I could use. Does anyone have an idea to go about his or a direction they can point me? Thanks in advance.