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The stainless steel body of Tesla's Cybertruck is reportedly leading to issues with gaps in between the panels
(www.businessinsider.com)
This is a most excellent place for technology news and articles.
How old?
Early 1900's: Yes. Metal panels had the same problem, timber panels did not (their thickness stops them from flapping).
Late 1900's: I don't think anyone used flat? There were definitely designs intended to look flat (esp 80's and early 90's), but there were still subtle curves to those panels to bias them and stop them flapping, as far as I recall.
Happy to be proven wrong :)
Okay, that explains it. Thanks!