Jeff's line about Troy playing the steel drums is clearly dubbed. On his Twitter account, Community creator Dan Harmon admitted the line was originally "kettle drums" and only realized the object in question was actually steel drums after filming was done.
Honda was the official sponsor of Community in Season Six.
Britta, Rick and Todd discuss going antiquing in a Honda, which comes from a 2015 commercial for Honda Fit. It's one of the commercials shown when watching Community on Yahoo Screen.
Both Elroy and Frankie are compared to their predecessors, referencing the fan discussions and criticisms about the recent changes in the cast. Chang speculates that it is unclear whether Elroy is "Black Pierce", "Old Troy", or "Shirley without a big purse". Later, Elroy speculates that the song "Pillar of Garbage" is about him, echoing Pierce's reaction to the song "Pierce You're a B" that Vaughn sang in Home Economics (2009). Similarly, Frankie asks what was so special about Troy, and immediately falls for Jeff's prankish answer by mistakenly learning to play the steel drums in order to fill Troy's place.
The Avatar Statement made in the scene With Britta Visiting her parents is actually a call back to English as a Second Language (2010).