For all the China lovers here it's not a clear sign of Chinese superiority. I saw a video on youtube recently exploring BYD. It's success is due to the fact that the Chinese government as part of their plan to dominate the global car industry gives them massive amounts of money. Which manufacturer can compete with that? European tariffs in the near future looks likely.
Among other things the video explores some of BYD's shadier practices including artificially inflating domestic sales and not paying suppliers for up to 9 months.
I have my doubts whether their success is sustainable.