* Definition of "classic car" varies: There's no legal definition. Some consider cars 25 years or older, others 30, and some use even more subjective criteria (e.g., collectability, historical significance).
* Registration data isn't consistently categorized: State DMVs don't uniformly track vehicles as "classic." Some might have special registration categories (e.g., antique plates), but many classic cars are registered under standard plates.
* Private collections aren't included: Many classic cars are in private collections and not registered for road use.
Therefore, any number you find will be an estimate, often based on surveys, market analyses, and extrapolations from limited data. You'll see figures ranging widely depending on the source and their definition of "classic."
