The interior of mine seems to taper in the deeper it goes. I think making a template from card stock first then trimming the plastic one to match is the way to go. I think I’ll just order it and fiddle with it until it works or I destroy it... we shall see. The navi console is slightly smaller so I should have enough material to work with.I will get you a depth measurement. I put it together first outside in the garage and it seemed deeper than I would like but once inside it didn't seem as bad.
I personally think the plastic is much nicer than cardboard would be and I think you could make it work assuming your console isn't bigger than the expeditions. You could do wood but I think that would be more work and I would want to paint it and not leave it raw. I guess you could stain it to match the interior trim and that could be cool.