There may come a time where Chinese sourced goods are superior in quality (imo only, coming very soon, many suppliers compete with each other).
Since at least entering 21st century, products made in Chia are often inferior mostly because buyers are only willing to pay cheaply. Expecting your $39.99 pair of jeans has comparable quality with your $399 or even $179 pair of designer jeans simply doesn't make sense at all.
With everything being equal (equipment, raw material, parts, manufacturing processes, ...) other than workers, I actually expect products made in China at least as good as those made anywehre in the world. Why?
While Chinese culture does not favor creativity, it does favor following set of rules. In the process of manufacturing, the opposite of individualism favors more consistent products. Remember Jack Ma once said that Chinese-manufactured fake products are just as good -- if not better -- than the real deal? There is actually some truth in it. And there are so many factors supporting this thesis far beyond this short post.
As to Tesla, as long as GF3 has the same robots, same or actually better general assembly lines etc. according to Elon, ..., there is no reason why Tesla cars made in China are not as good as made in Fremont, or even better - as stated by Elon that they are actually still improving quality.