Admittedly, my bed slippage fix is more designed for construction tools, but, I will add my two cents. I bought a horse stall mat, which fits in the bed, and is thick non slip rubber, it is stiff enough that the ribs of the truck hold it up so moisture doesn't get trapped under it. I have actually carried an open five gallon bucket of water placed at the back of the bed, not tied down and it just rode. (Of course I avoided quick stops.) As long as I tie the handles on the plastic bags to gather to keep groceries in the bags, they always just stay put where ever I leave them. Surprisingly even two, 2 litter bottles of pop don't move much when they have to roll the whole plastic bag.