With winter coming up I have some items that don't want to store in the cab or under the rear seat. Some items as tow chain or strap, bottle jack, tie down straps that I would rather have easily accessible when needed. List is probably endless, so I built some prototype boxes, had some scrap crap plywood, just to see how things work. Sizes can vary. I cleaned the spray in bed liner out of the holes for the factory swing boxes & lucky enough that who ever the dealer had do the spray in bed liner removed my factory tie downs before spraying so it was easy to remove the bolts needed to install my L brackets to hold the end of the box to the bed side. I made both sides different sizes. Just experimenting. Any thoughts & suggestions throw em out there.