Actually not all cars depreciate. ANd I'm not referring to collectibles.
A friend and his family buy exclusively Mercedez and have been doing so for over 30 years. One member purchased a very high end model which was very hard
to get in this area (or maybe everywhere else). Some how people found out that he got this Merc and were calling him wanting to buy the car. Some offers were as high as $20,000 above what he paid, he's very wealthy and very crazy about Mercs. So he kept it. He also has a 1990 SL 500 that has about 6,000 miles! THis past year he had a bad experience at the dealer and retalliated by buying a BMW 7 series.
and driving onto the Merc lot.
(He took it back after six months because he couldn't stand the I drive)
I guess its about Supply and Demmand sometimes with cars.