Early in the story, when team Arrow intercepts Helena's car, Roy is enraged at the driver for shooting him in the hand. To get Roy's attention, Oliver calls Roy 'Speedy,' which in the show is Thea's nickname. Speedy is Roy's nickname in the original comic book. They later discuss it and Roy expressed displeasure at the possibility of Speedy being his new nickname.
The intersection mentioned, Gail Street and Simone, is a nod to Gail Simone, who wrote on the Birds of Prey comic for many years.
Both The Huntress and The Canary were members of The Birds of Prey
In 2019, Birds of Prey (2002) was retroactively connected to the Arrowverse when Ashley Scott reprised her role as Helena Kyle/Huntress in the "Crisis on Infinite Earths" crossover event.
At the beginning of the episode the police are attempting to capture Hugo Mannheim. It's likely he's a family member of Bruno Mannheim, who appears in the comics as a senior member of the criminal group Intergang and is a frequent bad guy for Superman and several others.