Nicolas Cage thought Javi was the best written character in the movie, so much so he even asked to trade parts, as he thought playing his own biggest fan was more meta than playing himself. It wasn't until Pedro Pascal was cast that Cage eventually relented.
A sequence involving Nicolas Cage reprising some of his most iconic roles like Face/Off (1997), Con Air (1997), Leaving Las Vegas (1995) and Gone in 60 Seconds (2000), in a long black-and-white fight sequence between him and his younger self in a Surrealist German Expressionist set evoking of The Cabinet of Dr. Caligari (1920), was cut from the film as the studio thought it didn't fit the third act. According to Cage, the deleted scene will be released on home media.
At the end of principal photography, the whole cast was gifted a pillow with Nicolas Cage's face on it - each one autographed by him.
According to Neil Patrick Harris, Nicolas Cage had body makeup to cover his tattoos. When he asked Cage why Nick Cage the character doesn't have the tattoos Nicolas Cage the real person has, Cage said the character didn't have as many wives as him.
Pedro Pascal wrecked 14 prop cars during the acid trip running scene where he was required to bounce off the bonnet of a car. He was unhurt during this stunt.