I looked and looked and could not find a drop-in liner for an AD. I ended up buying two 4 x 8 sheets of diamond plate polished aluminum, 1/8" thick. I had a local sheet metal fabber bend up the sides which consisted of a 3 1/2" section that sits on top of the rails, then the sides, then about 3" along the bed. Custom installation all the way with lots of measurement and fitting but it sure looks nice. A 4 x 8 sheet in my area costs $219 so it isn't exactly cheap.
