The sugar cube wrapper that BoJack reads in the diner features a picture of his mother as a young girl and says "Sugarman Sugar, Family Owned* for Over 100 years! *Currently owned by the Fukusaka Family of International Conglomerates."
All of the actors who play Beatrice's family are Tony Award winners: Matthew Broderick for Best Featured Actor in a Play and Best Actor in a Musical, Jane Krakowski for Best Featured Actress in a Musical, and Lin-Manuel Miranda for Best Original Score (twice) and Best Book of a Musical. Colman Domingo is also a Tony nominee for Best Featured Actor in a Musical.
BoJack's fake name is "Hambone," a reference to the famous character of the same name from August Wilson's "Two Trains Running."
Based on the license plate county code of the Sugarman's car, their house is located somewhere in Kalkaska County, Michigan.
One of the girls in the hardware store is reading Petoskey Stone magazine - both a pun on Rolling Stone and also the official stone of Michigan, where the cabin is located.