Yeah
That was my initial response when I was still hung up on the actual "box" idea. If you look at the post dates the switch to using just a lid, and getting one built that worked right, took me over a year to accomplish.
All that wasted space was killing me and I just couldn't let it go.
I still like it though. Cool to open up my tailgate and see the first one in there, with half a dozen different coatings on it, piano hinge mounted to low so the lid doesn't quite open all the way, through bolts for the hinges that I realized were entirely unnecessary because they are always in compression, and then compare it to the new batch that have been made off a jig, with laser cut corners and a drill template for the holes, big difference there.
And now the tailgate list has a little over 60 people on it, the 1/4s, about half that, and a slowly growing list of 80 series tailgates that I have not even made a prototype for yet.