Quick post: After insulating the van, I added shiplap wood to one wall of the van. As of right, I have no clue what I am doing with the other wall. The hardest part was added the cleats to attach the wood to but aside from that, it was pretty simple. I used self-tapping metal screws to fix everything to the van. I have a nice turbine sprayer to spray lacquer but I didn’t want to mess with the clean up for so few boards, so I bought a spray can of white lacquer and sprayed the wood. I then added one piece at a time and when I got to a spot that needed a cut out, I just marked it and cut accordingly. Probably the easiest part of the van conversion to this point.