Ken previously warned Bart in Very Erectus (2016) to be more careful because she couldn't find Dirk Gently if she was locked up in a cell. In fact this is exactly how she found Dirk.
Mr Priest mentions that there were 42 original Blackwing subjects, yet another use of that number in the series.
The shirt Bart wears in the jail cell has QT3.14 above the left pocket. 3.14 is the value for pi, so the numbers and letters mean "Cutey Pie."
The book that Suzie's book club is reading is called Trillian's Lament, which is a nod to the Hitchhiker series.
The musical cue as Suzie goes to the book club is "Mr Sandman".