Whenever I watch a movie or TV show set in an earlier era, all the cars look brand new. In fact, better than brand new; the paint is rich and deep, highly polished. They all look as though they completed a full restoration yesterday. Streets full of cars like this look ridiculous to my eye. Why don't the moviemakers throw a little dust on some of them? Or use some old cars that have not been perfectly restored. Using these perfect cars detracts from the movie, IMHO.
Is this deliberate un-realism or just sloppiness? Other aspects of set-in-the-past movies and TV also tend to look brand new or "better" than they actually did: Paint on buildings, wallpapers, shop signage, etc. I even saw this phenomenon in a scene set in a black section of town in the south before WW2. It was totally implausible that everybody would have had a brand new car.