* DawsonCasting: Averted. Trash's age is never given but it is implied he's quite young. Mark Gregory was 18 when he did the movies.
* FakeNationality: Dablone is an Puerto Rican played by an Italian. Of course, this being an Italian film set in New York City, there's plenty of other examples but Dablone is the most blatant.
* RealLife/MeanCharacterNiceActor: Trash is a violent AntiHero on the movies with an ability to kill mooks and make things explode all over the place with just a handgun. The actor who portrayed him, Mark Gregory, who was a salesman at a shoe store in Rome before Castellari (the director) spotted him, was extremely shy, introverted, and hated stardom (which he never wanted). Which explains why he quit acting and vanished from public view in about 1989 and hasn't been seen or heard of ever since.
* YouLookFamiliar: President Clark from the second film is played by Ennio Girolami, who appears in the first film as an arms company executive. He's also the director's brother.