When Audrey picks up the fliers outside new-Nathan's house, one advertises "Capt. Trips" which is the name of the illness in Stephen King's "The Stand".
The episode title is a reference a Star Trek: The Original Series episode entitled "The Trouble with Tribbles. "
When Duke picks Audrey up, he instructs her to get in the back seat, and from where they are standing would have put her behind the driver. When they arrive in the parking lot, she exits the front passenger seat.
The phone number on Duke's card shows the actual area code for Maine (207).