Ditto what others are saying about the FarmTek product. Cheap easy to work with and perfect in that you can hook bungies anywhere to hold your load. Many floor options don't give you the ability to go through the floor and hook onto the rack itself for stability- poultry/kennel flooring does. Make sure you use UV stabilized HD zip ties to fasten it. IE not some Harbor Freight ones. I bought UV stablized ones online and was very happy with them. I think the entire cost for a full length 110 rack worth of material was less than $100 delivered. I got the interlocking/overlap which just means there is a flange so joints are stronger. Not going to work as a sand ladder though.
http://www.farmtek.com/farm/supplie...nt-ft1_poultry_fencing_flooring;pgha2215.html
I thought that looked like your flooring JG, I think that is the answer. It sounds like you all get four panels and trim to fit and you can't argue with the price. it will be nice to have something to help block the sun through the one sunroof I have and keep heat down inside when it's parked.