[Speedbumpauto]

I did mine in 3/4 oak veneer. Coated mine with oil based urethane on top and sides and the bottom with bed liner. it's good for 2 years and counting and has been rained on but is kept in a garage. It's a toy and it will never work, other than a beer chest and lawn chairs. You should consider the plywood is not the correct width even for my step side and will have to be spliced. I used a doweling fixture, 3/8 dowels, gorilla glue and clamps. You also need to know the wood will not go in in one piece due to the construction of the bed sides. I cut mine into 3 pieces and covered the cuts with polished strips, making sure the sides of the cuts were thoroughly covered with urethane. Even with the caveats, I think it's a great idea.