How do I verify Chinese used car VIN before paying deposit?

Require five things: (1) chassis plate photo — full 17-char VIN visible in single frame, (2) engine bay VIN stamp photo — must match chassis, (3) ownership certificate (机动车登记证书) scan showing matching VIN, (4) vehicle registration certificate (行驶证) scan, (5) walk-around video minimum 30s continuous with VIN plate visible in single sweep. Position 9 is ISO check digit — verify formula. Chinese VINs start with L.