This example build of a removable shelving unit in a 2013 Honda Odyssey (touring model) was done by Brian Murphy using a jig saw and other tools (no CNC). Images used with permission.
“ I thought I would share a modification I made to the Honda Odyssey to capture more storage space. There is not much 'extra' space in a minivan. Again, grabbing ideas from other successful builds I came up with the idea on adding storage shelves/cabinet in the rear windows. The face is 1/4" ply while the shelving pieces were made form 3/4" scrap from another project. No regrets but if I had to do it again, I would figure a way to make it foldable so it could collapse down for storage. ”