You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "how old does car have to be a classic?" whose answer is 20 years and older.
Each document should contain about 30 words, and these documents should contain useful information.

Query: classic car age definition
Useful Output:

Doc 1: How To Identify A Classic Car ; Veteran – Vehicles manufactured prior to 1918 ; Vintage – Vehicles manufactured between 1919 and 1930 ; Post
Doc 2: Generally speaking, most classic cars are at least 20 years old and have been well-maintained over the years. However, age alone does not make a
Doc 3: Classic cars are usually older vehicles with historical interest that makes them collectible and worth preserving. The intention of our Classic
Doc 4: Generally, cars at least 25 years old fall under the classic car category. However, the definition can vary depending on state laws, car clubs and insurers.
Doc 5: For insurance and registration purposes, the age of a classic car, in most cases, is at least 20 years old but not more than 40 years old.