Trivia: There were palm trees near the Popes' home in FL and there were palm trees when they stopped at a motel in SC. Palm trees are expected in tropical and subtropical climates, but certain species can grow anywhere in SC under the right conditions. (This is true to a lesser extent in the warmer zones of North Carolina.) The "Sabal Palm" (A.K.A. "Cabbage Palmetto") is actually South Carolina's State Tree. The palms at the motel looked like "True Date" palms to me but were more than likely "Sabals." (00:02:44 - 00:08:12)
Trivia: The film's original title was "Red Rain" and the Peter Gabriel song of the same name was meant to be featured in the film. However, they couldn't get the rights to feature the song, so the song "Red Harvest" was commissioned and written specifically for the film. Shortly before the film's release, the studio decided that the title "Red Rain" no longer made any sense without the Gabriel song in the movie, and instead retitled the film "Jack's Back."
Trivia: The demon effects were done by Carlo Rambaldi, who is arguably most famous for creating the design of the benevolent titular character from Steven Spielberg's "E.T."