"Unused" isn't quite the right term here. "Misassigned if they were to design their network today" or something would be more apt.

I had a networking job where we had a /16 legacy assignment nearly completely used but only one /24 "in use" according to what you could see from the internet. We looked at how the space was worth about a million dollars at the time but found it was not really worth it to try to move off anyways. Unfortunately, a lot of the devices smattered across that space were embedded devices where we had to pay bespoke vendors to come change the IP assignments or devices with IPs statically coded into home grown applications and every other sort of nightmare you could imagine. It'd have taken many bodies for a year + the associated costs + any of the operational fallout. At the following job we had roughly the same number of employees as Ford and our 10/8 was very tight as a unified network.

I'm not saying it would be as hard for Ford to try to find sub-blocks worth selling off or anything, just highlighting that waaaaay more of that IP space is being used than it seems from that picture and they likely do have a lot similar piece of shit equipment/sensors/building control and whatnot as well.