When Sanderson introduces Paul Kemp to Chenault, and asks if they've met before, Kemp states that he thought they might have met on the plane. This is a reference to the original novel, where Kemp first meets Chenault on the plane to San Juan.
The final black and white still shot (also the cover photo of the book) at the very end of the movie is not in Puerto Rico (where the movie takes place) but in Aruba. The author is shown sitting on a bench at the Aruba Palm Beach Club (with a bottle of Amstel beer). In the background is the Aruba Caribbean Hotel, the first resort hotel to be constructed on Palm Beach. The author visited Aruba while living in Puerto Rico.
The red airplane in the opening sequence is a 1974 Piper PA-18-150 Super Cub (tail number N8991Y). The movie is set in 1960, but this is not really an anachronism because the Super Cub was produced from 1949 to 1994 with relatively few changes.