Muscle Car Stamps

つい先日 USA で発売された記念切手、タイトルは Muscle Cars!!
切手を見てみると Forever とありますので てっきり Muscle Cars Forever かと思ったらそうではないのです。
この切手は一枚46セント, 普通郵便で封筒が送れる金額です。
しかし Forever と記されているので例えば今から 100年たって郵便料金が 10倍になっても
でもなぜ Camaro でなくて Chevelle の Convertible なんでしょう?

Recently in the USA, they released a special edition US Postage stamp, titled Muscle Cars!!
This type of stamp can only be released in America. Where the cars blend in with the country.
On the stamps, there's text "FOREVER" which I'm sure implies "Muscle Cars Forever".
One stamp is 46 cents, which is the price for standard letter postage.
However, since it has "FOREVER" on the stamp, after 100 years when the price is 10 times the amount, that means just one stamp will be able to be used without additional charge on a standard letter for postage.
On the back of the sheet of stamps are details to each of the cars pictured.
But I wonder why instead of a Camaro, they chose to use a Chevelle Convertible?

musclestamp-1 musclestamp-2