The 99th episode of the series. (Typically, the 100th episode of the series is considered a milestone and involves one or more special moments; this show chose to use the 99th instead due to the name.)
Amy details a flight to Monroe, Louisiana which has a small airport which only flies "crop dusters". Monroe has a real passenger airport, and it was where Delta Airlines was established - who got their start flying crop dusters.
Stephanie Beatriz publicly came out as bisexual at the time of the initial airing. She and the producers wished to include that part of her life in the Rosa Diaz character.
It was previously mentioned that watching Grimm gives Charles nightmares. Frederick Koehler who plays Charles' cousin Becca Boyle was previously on Grimm.
While guessing the name of Rosa's girlfriend, the final name Charles mentions is Moana, clearly a reference to the 2016 Disney film Moana (2016). Rosa actress Stephanie Beatriz would go on to voice the main character in another Disney film, Encanto (2021). Both films featured songs written by Lin-Manuel Miranda, who appeared in Brooklyn Nine-Nine as Amy's brother, David, in season 6's The Golden Child (2019).