You may not be familiar with Call Nick Ross, BBC Radio 4's Tuesday morning therapy slot for pensioners, the unemployed and the unemployable. It is an entertaining show characterised by genteelly incoherent attacks on the latest outrage - fat cat directors, say, or gay clerics.
This week's episode was well up to the mark as dozens of spluttering motorists rang in to "discuss" the topic of the moment: road rage. (Many of the victims, it emerged, had contributed to their plight by trying to explain the Highway Code to large men in Transit vans).
But what is this? Cutting through the babble we hear the smooth Scottish tones of a Mr George Turnbull, from Guildford, Surrey. With a sharp analysis of motorway madness, perhaps? Or shafts of redoubtable Scots good sense, garnered from the lanes of Fife?
Far from it. Mr Turnbull is the chief publicity officer for the Southern Examining Group, and all he had to offer was a shameless plug for the board's proposed GCSE in driving.
The diminutive Mr Ross was plainly baffled by this striking but irrelevant contribution. GCSEs are for 16-year-olds, he pointed out, and 16-year-olds are too young to brawl on arterial routes. Was the qualification devised to help prevent future road rage, he helpfully enquired?
Not at all, said the brazen Mr Turnbull, who continued to talk about something called vocational education. Only to be removed from the airwaves, without so much as a "thank-you", and replaced with fresh tales of Austin Allegros, crazed truckers and wheelbraces somewhere outside Basingstoke.