It is difficult to exact a window of time a car must fall into in order to attain Classic status. Officials maintain a car must be between 20 and 45 years old to be considered Classic, over 45 years is Antique Class, but this is only the very basic requirement – and the least debated.
The two most respected classic car associations in the United States weigh engine displacement, coachwork, accessories and brake systems amongst other factors in order to determine a car's classification. Although they may put their official stamp of approval on a car by declaring it "Classic", neither has the final word.
In the US, the Department of Motor Vehicles has a legal definition of "classic", which varies from state to state and is determined by that state's Antique vehicle registration. Most states agree, however, that a "classic" vehicle must be an original and not a reproduction vehicle, manufactured no fewer than 20 years prior to the current year. This vehicle must have been maintained in and/or restored to its original condition as per the manufacturer's specifications.
The taxation laws of older vehicles in the United Kingdom have led to these guidelines being used as cut-off dates for classification. Cars built before January 1, 1973 are exempt from the annual road tax and must display a license disc specifying it a "historic vehicle". A recognized body, such as HM Revenue & Customs, would verify any questionable entries.
Style is also a determining factor, even though a car may meet the age requirement of a classic, it stands to reason that a vehicle short in attractive features, both inside and out, would be out of contention. Yet, those with either attractive or innovative bodywork or mechanics may be considered classic while lacking one or the other attribute.
The condition of the car is paramount. Two of the same vehicles with the exact same specifications, one a pristine single-owner model and the other salvaged and restored by an amateur, may fall under different classifications depending on the guidelines of the evaluating body of the city or country. In the case of restored vehicles, despite all appearances, a salvage vehicle is valued at less than half that of a non-salvage vehicle and may not be considered Classic. A professionally restored body on a vehicle that is not road-worthy is of lesser value than a salvaged, restored vehicle that is, etc.
It is important to verify the standards of the governing body or bodies with whom you register your car. The slightest alteration, or an off-model windshield replacement, could crash and burn your classic car status.