Only episode to have just 3 actors appear (Andy, Barney and Otis). "Man In The Middle" (season 5) is next with 4.
The car Otis has is a 1933 Ford Model 40 Cabriolet.
This is another time when Barney, the notoriously bad singer, does a good job of singing.
Otis is driving again in Season 5, Goodbye, Sherriff Taylor.
The party where Otis gets drunk and passes out on the jalopy he bought appears to be at a house across from a church, given the style of the windows in the building seen behind Andy and Barney as they're watching the house.