Yes, I think cars should be considered a cultural expression. Especially in countries where they're viewed as status tools such as the US or Germany. Even though cars may be considered just a transportation device to some, Cars are also some of the biggest creators of cultural institutions out there. You have car galleries, You car shows, You have cars and coffee and so forth. Not to mention each culture has its own car to get represented with.
For example the American South may be represented with rods and customs, The Midwest with pick up trucks, The West Coast with perhaps with muscle cars and sports saloons and so forth.
Cars can tell a lot about a culture's or nation's status in technological achievement.
They may not be typically recognized as cultural expressions, But different cars do represent different performance standards for every country. How is it any different than classifying sports as a cultural universal? Besides that, Cars also represent their time periods by the cars letting us know what is always trendy,
Cars are technically considered a cultural expression, But no so much as other things such as fashion, Food or music. They're more of a personal expression if anything, A car represents a person's wealth and styling of expressing themeselves. But as a cultural expression they don't get as much of a recognition due to the fact that the majority just percieve them as transportation devices that get us from point a to point b. That's not say cars can't be considered a form of art or that cars do not have an iconic history, But their recognition as a cultural expression was more prominent when they were brand new.
Most cars, Even the stylish ones, Are made in an attempt to match the tastes of the customer.
Art is an expression of the artist. So a Ferrari made to satisfy customers is not art, Its a service of sorts. Ib order for that car to be art, It would have to be made and shaped purely according to the maker, Irrespective of what customers tend to like.
Now of course some cars are made as art, As an expression of the designer. Most are not.
What people want to drive does no reflect who they are but how they want others to see them.
Look at many of the people who own or want to own exotic sports cars. Odds are, They would never get even close to top speed because most will never see an open road.
Another prime example is the SUV's. These tend to be owned by soccer moms/dads. Tho parents like this use to drive station wagons, Or the mini-van that replaced them but instead wanted people to view them as being rugged and outdoorsy. That, For all we know, There is climbing gear in the back. Nope. Just soccer equipment as these vehicles are not likely to even be off paved streets.
Many people buy cars that are intended to reflect that they make more money than they actually do. Look at these people who drive expensive cars yet live in some dump.