No (NOT trying to get into an argument here!), my “80%” is looking at it entirely differently.
I just looked this up: (On the high end of consumer products) Toyota says an average car uses 30,000 individual parts.
https://www.toyota.co.jp/en/kids/faq/d/01/04/
Now, of course a lot of these, like the screw you mentioned, will be used in multiples - some in pretty decent quantities. But I’m betting there are at least 1000 different parts in an average car. Probably more like 5000. Even some of the screws are “custom” (may or may not really need to be). But - let’s go with 1000 different parts. (300 of this screw, one of that panel, 4 of that ring = “3 different parts”.)
So, even if the car is only 28% Chinese parts (by number of different parts, as opposed to, say, weight), that’s 280 different Chinese parts, a lot of them custom (for that mfgr., if not the car model). The vast majority have to be installed “when they have to be installed in production.” Any one of that majority of the 280 can shut some aspect of production down until supply can be re-established.
Just for fun, where does the mfgr. put all the other parts that ARE still en route, but can’t be run when they come in?
If only Toyota would sell their cheap small pickup with no frills in the US. There wasn’t much under the hood.