From a technical perspective, China's "National VI B (China VI-b)" is one of the strictest emission standards globally, with limits on carbon monoxide, nitrogen oxides, and particulate matter that are even stricter than some of Europe's Euro VI standards. However, the two are not legally recognized by each other, depending on your country's import regulations.

We will directly check the registration certificate (the big green book) and count the number of changes.

Absolutely. Even if you clear customs through gray channels, local commercial insurance companies will refuse to cover third-party liability insurance due to the vehicle not complying with national traffic laws; additionally, the vehicle will definitely fail the annual safety inspection at the local DMV.