John Bacchus is trying to sell his car. It is a 1964 MGB. In the episode we learn that the year the episode takes place is the same year 1964. If advertising the car for £100 he would have had his arm 'ripped off'. A new MGM would have cost in the region of £700. Being just a few months old and presumably pretty low mileage he could have taken it to a dealer and got £500 for it.