Anyone who has been a draftsman for a little while (or still is, CAD and all) knows all this already. When I first started, I went ahead and tried to find meaningful relationships with every bit of construction geometry. The designs that don't have this are crude and usually redrawn (working in employ you have to tolerate other shitty draftsmen). My own designs, and looking at other manufactured things I can easily see that the centerpoint of an arc happily coincides with other relevant geometry & et cetera; this is all obvious to a draftsman.
I've just never seen it linked to symbolism like this before, he is implying that it was culturally relevant way of engineering, which is new to me. Pretty damn cool
Peter was saying he doesn't know how prevalent this was. I can assure him, as many other draftsman could, that humans who are actually good at making technical drawings have been drawing this way for thousands of years. It's just that as an atheist I never really found any spiritual symbolism in the shapes themselves. All good designs use the golden ratio and other sacred geometry to define their shape, balance, profile et cetera. Draftsman who don't like their job never get into this sadly, so you don't see it in crudely drafted thing such as children's toys and other consumable products. BMW's engineers also rediscovered this way of design, as Peter did.
They call it the Efficient Dynamics Engineering Principles, in their own design firm. It is a rather comprehensive implementation to achieve emotional design. It is actually a funny thing to other engineering groups, because BMW's engineers are so old-fashioned that they had to take to explaining the design process as 'form follows function' in order to trick them into embracing it
We will see lots of neat cars from the BMW Group Design Division that embrace proportion soon enough.
But as I said, fully harmonized design principles and a fully integrated design philosophy doesn't surprise a draftsman, no matter how far back in time you go