Annette Day made in the movie, her screen debut - so far, it's her only role too. Producer Judd Bernard found her while he was with his wife shopping in London and entered an antique shop. Shop was owned by her parents. Judd Bernard asked her to have a lunch with him and talk about a part in a movie. Bernard, Day and Lee Marvin had lunch together in a hotel. Later Bernard went back to Hollywood, and soon Day got a message from him telling to travel to Hollywood and make a screen test. She got a role in the movie.
One lucky Elvis Presley fan bought a jacket as a gift to Elvis. Elvis told her to watch the movie carefully when it came out. The film came out and she saw that the jacket was in the suitcase which belongs to Elvis' character on film.
Although the film is set in Europe too, Elvis Presley never filmed outside Culver City, California. Second unit filmed in Belgium with body stunts; Joe Clauwers for Elvis Presley and Paula Geerts for Annette Day.