Max is right about passenger cars and transit vehicles, we have international manufacturers who assemble in the US, with both domestic and foreign content. We have no major "purely domestic" passenger or transit manufacturers. We do have international manufacturers using American labor and significant American components, who have set up assembly plants in the US for passenger cars and locomotives. Freight cars are another matter, with overwhelming US manufacturing dominance of the North American freight car market. The US is also a major worldwide manufacturer and exporter of locomotives.

We have had a "protectionist" market policy, with the "buy America" provisions in FRA and FTA funding, for over forty years of my career. And, which over that period was more or less a complete failure in keeping domestic firms in the market. We even had incompetent firms like Morrison Knudsen use this phony "Buy America" nonsense, as "political leverage", in order to force us to buys passenger cars that actually had way less US content, than their "foreign" Canadian built competitor Bombardier.....

I'm not sure the "sky is falling" quite yet, but it is an interesting spin on the trade issue.