I'd love to see a company specialize in taking older technology, and only improving on it by incorporating modern materials science to make more reliable and higher build quality versions

Right? It seems like such a no brainer. Someone is going to bring back old boxy cars and make a fortune. Imagine they re-issued the E30 and didn't muck it up too hard? Or any number of popular old cheap models.

So you're thinking something like https://www.analogue.co/?