Derek Griffiths provides the voice of Kelly's car and an indignant customer in a pitch-black restaurant, though is uncredited for both roles. It's notable that when the lights are switched on in the restaurant he's not there in person, as if Kelly's team thought he had the right comic voice to "sell" the humour, whereas extras play the actual diners.
This episode did not chart in the BBC2 top ten that week; the joint ninth rated programmes both had ratings of 4.05 million.