YSK: Always have a mechanic YOU trust inspect a used car before buying, even if buying a "fully certified" car from a dealer. A professional inspection will provide an important extra level of insurance that you're not buying a pack of trouble.
from /r/YouShouldKnow
YSK：在购买二手车之前，一定要让你信任的机械师检查二手车，即使从经销商那里购买 "完全认证 "的汽车。专业的检查将提供一个重要的额外的保险，即你不是在买一包麻烦。