The Father Christmas Suit - S2-E11
Continuity mistake: In the scene on the way to the church when Liz and Hyacinth nearly crash into the Thorgunburys' car, there are two cars parked in the front garden of the house behind them, a red Peugeot and a white Citroen. At the end of this scene a white Vauxhall Nova has just appeared in the garden.