Another good indicator is the price of aluminum in China versus the U.S.
China consume a lot of AL, for the auto industry both internally and in the export of parts. When the bottom dropped in the U.S., the Chinese were still consuming at a strong pace.
"“Even with the decline, there is speculation that these figures may still understate economic slowing,” a new paper from the Dallas Fed notes, referencing the official GDP numbers, but making the point that China’s data are notoriously unreliable. “Economists have long doubted the credibility of Chinese output data. "