I've used this a half dozen nights by now, and have found it perfectly usable, despite of its very simple construction.
It uses a single 4x8 sheet of plywood - cut to: 48" x 76". The edges are taped with duct tape, and the end that goes against the seat have a strip of camping foam hot glued to protect the seats. The 12.25" long 2x4s have a .75" long protrusion that fits into the holes made for the 3rd row seats. The whole thing tilts about until you back your front row seats back and push it gently against the rear gate. That's about it!. Oh, I put foam pads against the folded down 2nd row seats to protect them from the plywood - a couple of extra thicknesses over the shorter seat as it is a bit lower when folded down.
Gil
Ventura
It uses a single 4x8 sheet of plywood - cut to: 48" x 76". The edges are taped with duct tape, and the end that goes against the seat have a strip of camping foam hot glued to protect the seats. The 12.25" long 2x4s have a .75" long protrusion that fits into the holes made for the 3rd row seats. The whole thing tilts about until you back your front row seats back and push it gently against the rear gate. That's about it!. Oh, I put foam pads against the folded down 2nd row seats to protect them from the plywood - a couple of extra thicknesses over the shorter seat as it is a bit lower when folded down.
Gil
Ventura