All states waive certain fees and tests for vintage cars. Most states waive those same fees and tests for classic cars also. But determining whether you have a vintage or classic car can sometimes be confusing.
Antique car. An antique car is a classification that is often set by state law. States often have a special type of license plate for these cars. For that reason they set rules stating what qualifies as "antique." In most cases it is a car that's over 45 years old. Generally the car should be maintained in a way that keeps it true to the original manufacturer specifications. These rules vary by state.
Classic car. This classification definitely overlaps with antique cars. The definition of classic car is actually quite similar to that of antique cars. A car must be at least 20 years old, but not more than 40 years old to be considered a classic car. It should again have been repaired and maintained in a way that keeps it true to its original design and specifications. In other words it should not be modified or altered. In addition, many add a stipulation that the vehicle should have been manufactured no earlier than 1925. For these reasons all classic cars are also antique cars, but not all antique cars are classic cars. Are you confused yet?
Vintage car. There is also overlap between vintage cars and antique cars. Some vintage cars quality as antique cars, but not all vintage cars are antique and vice versa. Different groups set different cut off points for what qualifies as a vintage car and what does not. Generally, cars that are considered Vintage were manufactured between the years of 1919 and 1930, but some end it at 1925. Unlike the other two classifications, having had modifications does not necessarily keep a car from being a vintage car
Stock car. A stock car will have the general overall look and feel of a a car as it was originally manufactured. Rules vary according to which show or class a car may be part of. Essentially, the xterior, interior & engine compartment must appear stock. Electric cooling fans are acceptable. Upgraded radio system allowed as long as it fits the original opening. -Vehicle equipped as they were delivered from the factory or selling dealer. Radial tires & aftermarket rims allowed if they are stock size for the year. Engine changes are allowed if rebuilt engine is correct for year & model. Chrome air cleaners, chrome valve-covers & number of carburetors must be correct for year & model. At most car shows, cars intered in a stock class may contain up to 3 changes as long as the car regains the "stock look feel and general appearance. Here again, this varies by location.
Modified Cars. Original stock cars which have a limited number of modifications from the original design. Examples of modified class would be additional non-stock chrome and/or billet aluminum (up to a specified number of items items in the engine compartment will count as one modification). -Aftermarket steering wheel, aftermarket shifter & non stock radio. Non stock carburetor, intake manifold, exhaust headers, ignition, etc. It would also include a different than stock engine. (Example-a Mustang came with a 289 and now has a 390 in it). It can also include non stock stripes, graphics or change in battery location.
Custom Class. This would include cars with altered suspension such as -Lowering, Rack & Pinion or Air-Ride; Non-stock turbo, supercharger or NOS system; Chopped, “frenched”, shaved or altered body panels; Custom paint (Example-non-stock colors, candy’s, pearls, flakes, etc.), paint graphics, Painting of stock chrome bumpers & window trim; Engine position change (Example-forward, backwards or sideway’s); Engine swaps (Example-putting a Chevy in a Ford or putting a 502 where a 350 used to be); Aftermarket body-New manufactured body’s of car model’s (Example-’41 Willy’s, Mustang’s and Camaro’s); Interior material not offered stock (Example-tweed or leather where vinyl used to be.).
Racing Classes. When it comes to race cars, you should be aware that the rules change yearly by the association governing the specific type of race. NASCAR Sprint Cup races have different rules than say the Winston Cup races, although the cars might look similar. What may be allowed one year, may not be allowed in the following year. It's best to research your category carefully.