Wow, and absolutely brutal amount of work must have been put into those reports. How do they estimate the cost of parts made inhouse?
There are fixed costs and variable costs for production. Creating the dies and molds is a very large fixed cost which gets spread across all units created. Based on the size of the part, estimated tolerances required for successful operation, and other factors, an estimated die or mold cost could be created.
The material, electricity, and labor are variable costs of production, all of which can be quite easily estimated.
Now, on the rear view mirrors they had cost down to the penny. Unless they have some other datasources they're using, I'm guessing it's an estimated cost. Unless I learn more, I'd be skeptical of those prices. I'd be more comfortable if they posed an estimated cost per component and rolled it up into an estimated cost for the rear view mirror assembly.
https://commons.wikimedia.org/wiki/File:Dvi-cable.jpg
This image shows a small amount of flash (extra material where two halves of a mold meet) on the edge near the screw. The main question was how the plastic housing was manufactured. The piece I gave him had no visible flash. It was either two pieces attached together (with an adhesive, solvent bonding, or ultrasonic welding) or the metal plug components were inserted into the mold and the plastic was injected (overmolding).
He suggested overmolding because there was no seam to be found. Even feeling the edge felt like one piece. There was some misalignment on the screw hole though, which was the reason it couldn't have been overmolding.
I do think, many times, Musk's contributions to various fields have been overblown. However, I do think that Musk's companies' do challenge incumbents to really re-evaluate their internal processes, costs and organization. If I were General Motors, I would think it foolish to ignore this Munro report entirely.
In that way, the market is working as expected in my view.
https://jalopnik.com/the-fascinating-company-that-tears-cars...
In short, get a bunch of experts together and review each part, then add up the result.