There is a Mahler mention in the recent film "Shutter Island".
Briefly, early in the movie two U.S. Marshals walk into a doctor's office and on the phonograph the Mahler Piano Quartet is playing. The doctor asks them if they know what's playing and the Mark Ruffalo character says "Mahler".
One problem, the movie is set in 1954, and according to the Kaplan Mahler Discography, there wasn't a recording if it until the 1970s.
In a slight aside, I have to admit that in the forty years of collecting Mahler, I've never purchased the Quartet, probably because I don't have a great interest in chamber music, and the work is so early Mahler, that it just doesn't "seem" like Mahler at all. That being said, would I be mistaken if I said that most of Mahler listers here would not be readily able to identify the quartet if they heard it playing? (Let alone a young cop in 1954!)