When waiting in the car at the 36 minute mark, Ashley Walters raps the words from 21 Seconds by So Solid Crew. Walters once went by the name of Asher D and was in So Solid Crew many years before becoming an actor.
Features Robbie Gee as a barber. Robbie Gee starred in the film Haircut and came to prominence in the 90's comedy show Desmond's which took place, almost entirely, in a barber's shop
When Bishop arrives at Pike's house he asks Pike's wife whether she has changed her hair. This is a joke alluding to the fact that not only has her hairstyle drastically changed from the first series but she is also an entirely different actress.