With the disclaimer than I'm not in America or an American could I suggest including American Graffiti. There is an interesting contrast in the film between all the "attractive" guys with their fancy (and fast) cars and one of the main characters being a nerdy deep thinker type driving a 2CV.
Ads are also a great way to see how things change over time - the 40s and 50s super optimistic future "jet" looking cars, 60s "good life", late 60s muscle and then into 70s nervousness about energy supply and cost, and where they start to push MPG etc.
Also those good old "public information" films that used to be made.
The Internet Archive is a good place to see lots of these.