As many folks have pointed out, it depends… Not only on your personal definition of “classic”, but the state government that creates rules for tagging certain cars, and the buying public, which drives the market for classic cars.
Your car, for instance, has value to you, and to maybe other Saturn owners, but putting it for sale might give you a real idea of what the car might be worth to the public at large.
In Pennsylvania, it used to be that if your car was 10 years old or more, you could get “CLASSIC” plates for the car, which were great for a number of reasons. This was bsck in the 70’s and early 80’s, when cars lasting 10 years was somewhat of a novelty. Now, 10 yer cars are all over the road. I own one, and don’t consider it a classic by any definition.
In PA, the ANTIQUE plate can be put on your vehicle provided it is 25 years old, and in good shape (you used to have to send photos in of your car, but I’m not sure that’s still the rule). Pa used to hae a great purple plate with white numbers for the antique plate, but someone in Harrisburg decided to change it for who knows why to something similar to Connecticuts. It is an awful plate, with an REO Speedwagon or something on it. It looks so bad, many folks opt to leave regular plates on their car instead of getting the antique plate, which brings significant money savings advantages (no annual inspections, lower insurance rates, etc.). But you can’t put that stupid plate. A 1965 corvette and think it makes the car.
“Classic” also has to meet a certain leel of style and panache. A Chrysler K car, for example, saved the company, but they aren’t being sought out by too many people, and no one is restoring them.
So, I would say this… For classic cars, anything over 25 years old that is being collected actively by the car community, whereas an antique just needs to be 25 years old. But these are my definitions. I think a corvette of 25 years ago is a classic automobile, but a Buick skylark? Not so much? What about a Chrysler LeBaron? No.
So the car has to be sporty, have a market of interested buyers and restoration hobbiests, and be on the rare/expensive side.
If thst Edsel someone mentioned upthread is salvagable, take a look at it and get a price. It could be worth buying it for parts alone, but there are many Edsel clubs across the country, and people will pay good money for a nice looking Edsel.
If you look at card produced over the last 10 years, I think only three will become real collectors items… The mustangs, camaros, and the challengers. All cars retro’ed from the 60’s muscle car era.