What Makes A Car A Classic?

It seems that everyone has their own idea about what makes a car a classic.  Obviously, classic cars are older vehicles, and very generally speaking, those that are 20 years and older could fall into the classic car category, however there’s more to a being a true classic car than just the age of the vehicle.  I think it has more to do with the popularity of a car and whether it has gone up in value over the years than anything else.  The look and style of an old car certainly has much to do with whether or not it is considered a classic.