They are all done by 49/51 JVs, so it isn’t Toyota making the cars, it is GAC Toyota. My observations are all anecdotal and shared by Chinese colleagues when I was working in China. They are starting aggressive programs to automate (e.g. https://www.nytimes.com/2017/05/12/business/a-robot-revoluti...) and quality should improve over time.

Note that it doesn’t really bother most people because while the defect rate is higher, the mechanics to fix those problems are cheaper as well.