Gourmet Night (a.k.a. Gourmet's Paradise) - S1-E5
Revealing mistake: When the Colonel first meets Basil, the same shot is used twice of the Colonel twitching.
Gourmet Night (a.k.a. Gourmet's Paradise) - S1-E5
Revealing mistake: When Basil is out of the car and shouting at it after its final breakdown, you can see a crew member reflected in the right hand side of the windscreen giving John Cleese cues. It's not Cleese himself, as the reflection remains after he runs out of shot to get the tree branch, and the reflection doesn't mimic every action performed on screen.
Answer: It's "Leisure Complex" by Dave Gold and Gordon Rees. Can be found on YouTube. The relevant clip is around 25 seconds in.