The commentary doubles as a synopsis, and is reproduced in full below:

Many of Scotland's 80-odd coal mines are in remote and beautiful parts of the land. Pennyvenie mine is near Dalmellington, and most days, as the morning shift ends, you can see a sedate black Vauxhall nosing out onto the road. West a mile or so, then up a dirt road, to Farmer McLellan's yard.

Driver of the family car is Walter Brown, an engineer at Pennyvenie and, for the last two years running, stock car racing driver of the year. He spends his afternoons working on the new hot rods, which he counts on to help him keep that title. These cars are single seaters, and Walter's Number Six started life as an MG, before he worked her over. Number Six is no elegant carriage, but her voice certainly carries a note of authority.

At home, the trophies attest to Walter's skill. The three boys are as keen on racing as their father, and Mrs Brown is the kind of woman who can put up with a half-built motor on the kitchen table.

For practice, Walter uses some nearby colliery roads with another stock-car racer to pace him through the bends. For Walter Brown, next stop will be the World Stock Car Finals in London this autumn. The best of luck!