TRIVIA: When Bo Peep gets taken away, the car driven by the new owner has the license plate RMRF97. it's a sort of meta-Toy Story 2 (1999) reference. It's an often repeated story that the second Toy Story film was nearly entirely lost when the main file was accidentally deleted from the main Pixar servers. This license plate references the computer command which nearly erased the movie. the Unix command "rm", with "rm -rf" standing for removing all files recursively in a given directory and without confirmation. Thankfully, a pregnant employee had a backup copy of the film on her home computer, which had to be gently driven to Pixar HQ in order to save the movie.

Second Chance Antiques was one of the hardest locations for the Toy Story 4 (2019) team to create, because of the breadth of items that had to fill out the cramped second-hand store. "Fortunately, at Pixar, we have a big 'backlot' of objects from all of our feature films," production designer Bob Pauley told The Hollywood Reporter. "It was a big treasure hunt because we have a lot of interesting history, and we also took the opportunity to plant some fun Easter eggs," added supervising technical director Bob Pauley.

Duke Caboom is obviously inspired by real-life stunt man (turned kid's toy) Evel Knievel, right down to his Canadian garb spoofing Knievel's red-white-and-blue costume. But it goes further; Knievel's motorcycle toy was advertised on commercials like the one seen in Toy Story 4, most with the toy performing impossible feats that set expectations that the real thing could never match.

The carnival worker has a tattoo of the pizza planet truck on the back of his leg.

Gabby Gabby is a nod to the popular Chatty Cathy dolls of the early to mid '60s.

Woody pretends to be a phone in the antiques store. Woody's pose holding the receiver of an old touchtone phone, is meant to look like the classic Mickey Mouse phone that was ubiquitous in many homes in the 1970s and '80s.

Speaking to Norton, Tom Hanks revealed voicing the latest, and perhaps last, Toy Story film was especially emotionally exhausting saying: "It was terrible. I started recording Woody in 1991 and each film takes about four years. "It was my very last session and when I'd said the last line they said, 'Okay, great, thanks,' and just like that 24 years was over. All I could say was 'Oh my, oh my' over and over again and my bottom lip started quivering. I got in my car and drove away with the music playing and the credits rolling in my head." Finding the voicework tiring, he said: "I never began a recording session without wishing it was already over. Woody is clenched all the time. It's exhausting." 

Tom Hanks got wistful when talking about recording his last lines for the movie. The only experience he's had remotely like it is the curtain call of a Broadway show's final performance. "The thing is about plays, they disappear in the wink of an eye," Hanks says. "They're never seen again. They no longer exist at all except in the collective memory of the people who came and saw it. I have great-grandkids that have yet to be invented who will be saying, 'Hey, that's my great-grandfather's voice (in Toy Story(1995)).' And it will last because they're still watching 'Snow White' and they're still listening to Jiminy Cricket sing the same songs, and the same will be for me. And that's a big concept to try to grasp."

The music played on the phonograph when the dummies are introduced in the antique store is "Midnight, the Stars and You," the same song played over the final scene of the Stanley Kubrick version of The Shining (1980).

When Woody first reunites with Bo Peep, her sheep bring her various items they scavenge and think they can use. One of those items is the Grape Soda cap from Up (2009) that Ellie pinned on Carl's shirt. The pin becomes hugely important to Carl and at the end of the film he gives it to Russell as a token of his appreciation and friendship, except Bo Peep has zero interest in it.

One of the recorded phases in Buzz Lightyear that is heard when he presses the buttons on his chest is "Open the pod bay doors!" a reference to a famous line from Stanley Kubrick's sci-fi film 2001: A Space Odyssey (1968).

When asked to voice Forky, Tony Hale said, "A utensil's existential crisis? I'm in!"

According to producer Mark Nielsen, "The dummies are, by far, some of the creepiest characters we've ever created. Our animators really leaned into the truth in materials for how our ventriloquist dummies move. Dummies' bodies are soft with no structure, so our dummies' arms just dangle and their legs bend backwards. Throw in their fixed expressions with their wide eyes and big hinged jaws and they're nightmare material in the best way possible."

This film marked John Lasseter's final involvement with Pixar Animation Studios before he exited the Disney company as chief creative officer.

The divers mask (P. Sherman) from Finding Nemo (2003) can be seen on one of the many shelves at the Antiquity shop.

Tom Hanks (Woody), Tim Allen (Buzz Lightyear), Wallace Shawn (Rex), John Ratzenberger(Hamm), Debi Derryberry/Jeff Pidgeon (Little Green Men/Squeeze Toy Aliens), and Frank Welker (Animal Vocals) are the only cast members to have appeared in all four films of the Toy Story franchise. This does not include Don Rickles (Mr Potato Head) in which they used archival recordings for the character due to Rickles' death, the same said for John Morris (Andy) who only voiced the character in the flashbacks.

In the closing credits, Duke Caboom gets his mind blown and announces "Whoa," the most famous line from The Matrix (1999) spoken by Duke Caboom voice actor Keanu Reeves.

The casting for the role of Duke Caboom was accomplished by using a blind audio test containing audio recordings of line readings from Canadian actors played for director Josh Cooley with producers Jonas Rivera and Mark Nielsen. Neither of them knew which voice belonged to which actors except for the casting department who recorded those recordings. When they heard Keanu Reeves' voice, they immediately stopped the test, realizing that he was the right fit. The thing was, it was envisioned only as a "gag character," Rivera recalls -- a Canadian daredevil action figure named Duke Caboom, a stuntman evocative of Evel Knievel's era, who might get a few one-liners. Soon, the "John Wick" actor pulled up to the Emeryville, Calif., studios riding his motorcycle -- and he had questions. "Is Duke mad at Rejean?" Reeves asked, referring to the boy who had owned the toy, Rivera recounts. "Is he mad at the TV commercial" that popularized him? "We were workshopping this character over lunch," Rivera says, and Reeves "started to become Duke right in front of us, doing the [karate] chops and getting on a table in the atrium. People walked by [in disbelief]: 'Is that Keanu?' " "He became that character -- really emoting and getting into it -- no different from any other role. He's a delight to work with." By the time the collaboration was complete, Duke Caboom was a fleshed-out, scene-stealing character -- another highlight, too, in Reeves's banner year.

Among Jordan Peele and Keegan-Michael Key's more memorable improvisations in the booth is a song Ducky and Bunny break into when they find out they're on the way to meeting their first-ever kid, an anecdote Key recounted on The Tonight Show Starring Jimmy Fallon (2014): "They put a bunch of lyrics down for us one day and said, 'we're wondering if you could just kind of burst into song. And we're like, 'Oh yeah, whatever song you want.' And they're like, 'No, we don't really have the song. Could you write a song right now?' We sang for 20 minutes straight, they recorded for about 30 minutes, and there's about five seconds of it in the movie."

Forky, the craft spork toy made by the film's kindergarten child Bonnie, wasn't designed solely by computer or on the drawing pad. Instead, in an exercise nodding to Bonnie's mode of creation, Pixar held a "Forkshop", a workshop in which crew members created their own real-life Forky design models out of pipe cleaners, googly eyes, Popsicle sticks and, of course, sporks.

Tinny from Tin Toy (1988) has a rather unimpressed reaction when he meets Woody. This may be a reference to how Tinny was originally set to be the protagonist of Toy Story(1995) before he was replaced with Woody.

The voice of the TV announcer on the Duke Caboom commercial is Flea from the band Red Hot Chili Peppers.

The motorized toy skunk runs on BnL batteries a reference to the corporation Buy n Large from WALL·E (2008), which basically enabled the pollution on the planet forcing humans to leave earth.As the toys flee from the Bensons, they fly past an old looking square box with the word 'pixar' labeled on it. This is a vintage 80s Pixar Image Computer a graphics machine developed by the company when it still belonged to Lucasfilm. (It also is used as the logo in some of Pixar's older short films). 

Ariel's necklace from The Little Mermaid (1989) can be seen inside the Antique store.

The fifth Disney's animated film to score 100% on Rotten Tomatoes, after Pinocchio(1940), The Many Adventures of Winnie the Pooh (1977), Toy Story (1995) and Toy Story 2 (1999).

Gabby Gabby was also inspired by the talking doll Talky Tina from The Twilight Zone(1959) episode "Living Zone".

This installment reveals that curse words do exist in the Toy Story universe, if the scene where Mr. Anderson is about to use "some words" after the tire gets flatten is anything to go by. While it would be odd in other fictional universes for characters to never or very rarely swear, here it actually makes sense. The toys hang around young children constantly, so naturally swearing isn't part of their vocabulary.