How should I handle “oem vs aftermarket for automotive replacement parts and accessories” when shopping for “automotive replacement parts and accessories”?

Start with the full 17-character VIN, then confirm year, make, model, engine, trim, drivetrain, and the OEM or interchange number printed on the old component. NHTSA explains that a VIN identifies a particular vehicle, but the seller or manufacturer still needs to confirm application-specific fitment. Verify the final application and written terms with the part manufacturer, seller, or installer before purchase. Name the documents to keep: VIN note, old part number, listing screenshot, receipt.