I agree with you, but one point I see everyone missing is the fact that this is a first-time installation of a new technology that hasn’t scaled. There needs to be a business plan of course. At the same time, no one would expect to see ROI figures for the first build of a concept car.
That's because concept cars aren't investments. This project is an investment. Investors invest in investments to get a return on their investment (ROI). Car buyers, other than car dealers and outfits like Budget Rent-A-Car, do not buy cars to get ROI. Advertising an investment without publishing any projected ROI figures (the business plan you mention) is like advertising a concept car without publishing any photos, video, or drawings.
