In the yellow pages, the address of the PI is on Dahl Ave. - a joke by the art department to the director, before they knew the address would be visible on-screen.
Joanne Whaley-Kilmer's new name "Vera Billings" is a combination of the town (Billings) where writer-director 'Dahl, John' is from, and a girl he dated.
The semiautomatic pistol that Fay loads with a fresh clip in the white Cadillac suddenly becomes a revolver when she points it out of the car's window and fires at the police officer following them.