According to Nick at Nite, this was the last original episode filmed. In the 1990s, Nick at Nite showed Taxi episodes in the order they were filmed instead of the order they were aired.
Danny DeVito, Christopher Lloyd, Scatman Crothers and Vincent Schiavelli all starred in One Flew Over the Cuckoo's Nest (1975)
The character Walt - played by Scatman Crothers - mentions watching Gilligan's Island on his TV. Crothers acted in a Gilligan's Island TV movie "The Harlem Globetrotters on Gilligan's Island" just a couple of years before this show.