except the fab pays the tooling cost once per process and the tool and die company charges once per design.

I've actually worked a little on hydroforming, but unless you're thinking of a different kind, it was labor intensive, and prone to crinkling in bad spots. we basically concluded that we used less time and got a better result with an English. which would probably run at least $10k for a car body, if you could find someone willing to work for that low an hourly rate.

Again, I'm confident that this is not a viable business, and certainly in no position to make it a viable business even if it was...

But places that make windshields keep forms around and make runs of windshields even for low volume cars; obviously there's less recurring need for fenders or floor pans... But there may be some way to financially engineer a "do a run we pay X per unit; hopefully that results in doing another run and paying X, and if we can get to 100X the per unit costs go down to some other target.

But I was thinking, and perhaps they should just make these cars out of ground up trabants or saturns. Tesla has demonstrated that some customers don't actually care about perfect finishes or gaps or whatnot; I certainly would be fine with a car made out of trabant, especially if it meant I didn't have to worry about dents...