The diner that Jimmy and Kim meet at is called El Camino (which is the name of the Breaking Bad movie).
In the opening sequence, one of the items being removed from Saul's home is the Ritchie Blackmore-autographed guitar Saul gets in Episode 3x07.
On January 17th 2020, AMC Announced that Better Call Saul had been renewed for a 13-episode sixth and final season. It was slated to air in 2021, but was delayed to 2022 due to the Coronavirus pandemic.
The cold open marks the second time events are depicted that take place during the time-line of Breaking Bad (2008), but were not explicitly shown in the parent series.
In the scene when Nacho Varga walks into the hostel, the receptionist is sitting on her chair watching a scene from Argentinian TV show "Casados con Hijos" ("Married with Children", an adaptation of the American sitcom by that name), widely considered to be one of the best Latin-American sitcoms ever created.