That may be a factor, but Germany is maybe the country in the world with the most auto industry. Possibly tied with Japan.
And while Japan favors USA, which may be in line with your thinking, Japan has always had problematic relations with China. Which is a more likely explanation IMO.
Still Germany favors China, so that speaks against your idea. And what's notable is that most traditional American allies, now doesn't even favor USA over China which has been a strained relation to mostly all those countries for a long time.
I think what pisses people off is that USA is clearly abandoning their allies, friends and core values about international law and both political and trade relations, we've agreed on for more than 80 years.
USA abandoning Ukraine after they promised to protect Ukraine when they gave up their nukes, is a very strong political signal that USA can't be trusted as a friend or ally.
We don't expect much from China, as long as they don't invade Taiwan that's a plus!
With low expectations it's much easier for China to live up to them.
USA on the other hand, is failing completely with Trump threats lies and manipulation, and not only Trump, but the entire administration and MAGA and GOP. So USA is looking more and more as no better than China.
And with China being the more reliable of the two, the favor tilts towards China now!
It's really really sad that USA has fallen so deeply away from decency and respect of human rights, and have so little intention of following any promises previously made in international political agreements. Fuck Trump even abandoned his own trade agreement with Canada for no rational reason! And USA is threatening to invade an allied country!
IMO this has little to do with working in a car factory, but much more to do with Trump creating insecurity, and fucking everybody over, and looking more and more like a Nazi doesn't help either.