What is the 25-year rule for importing JDM cars?

US federal law (the Imported Vehicle Safety Compliance Act) prohibits importing vehicles less than 25 years old unless they meet all FMVSS safety standards. This means a 1999 Nissan Skyline R34 becomes legal to import in 2024. The clock starts from the month of manufacture, not the model year. Some states have additional requirements — California is the strictest with CARB emissions compliance.