I suspect the turntables were never built because the dimensions don't work. This plan is 14 feet wide, and the typical upper-class car was 14 feet long.
One of the garage plans shows an interesting form of construction that would work nicely for a small house.
Steel frame, steel slats, concrete on and around the slats. Totally bugproof and fireproof and rainproof.
= = = = =
Looked up the Hy-Rib tradename. It wasn't just slats, it was a complicated ridged mesh system. Albert Kahn owned the company and used Hy-Rib extensively in his famous buildings. Hy-Rib could form arches and domes of any shape.
Detail 1:
Detail 2:
Main building at SMU in Dallas when new:
Still there:
Hill Auditorium at UMich when new:
Still there:
Best of all, Hy-Rib construction was war-resistant.
[The last picture led to another interesting story.]
The current icon shows Polistra using a Personal Equation Machine.