I just saw The Artist, a modern silent movie, and I thought it was great. It's playing in most theaters now. A 1935 Cadillac and Pierce Arrow are in the film. The articles below mention a Bugatti, but I think it was a Packard, the second car that passes by a theater at the beginning of the film.
It's a fun movie. I'm visiting Wash DC for the holidays. The audience here was silent, yet we were watching audiences in this silent film watching a silent movie. We could tell those audiences weren't silent at all...applauding, talking to each other, and to the actors on screen.