The definition of a classic car is hard to pinpoint. For insurance and DMV purposes, however, each state has a law that states what the age of the vehicle should be. You should look up what it is in your state.
Depending on whether vintage and classic terms are used, then vintage would be classified as anything older than late 1940's and classic would be late 1940's through late 1970's. I'm sorry that this does not help you, but you should figure out if there is a law stating a specific number of years (like 15 or 20) that would work in your favor.
