It makes you proud to be British: a young lord with no racing experience inherits some money, decides to fund a racing car to enter Le Mans and finishes fourth.

Now the 1939 Lagonda V12 is going for auction, where it is expected to reach over £1 million (in real terms that is not far off what Lord Selsdon spent in the 1930s). It will be on display at the Goodwood Festival of Speed and will go under the hammer at the Bonhams Goodwood Revival sale on 15 September. Its value is partly due to its racing heritage and partly because it is one of only two such cars ever built.

Funded by 26-year-old Lord Selsdon's newly-acquired £65,000 inheritance, close friends Selsdon and Lord Waleran used the journey to Le Mans to run the car in – not for them the drudgery of testing. Compared to the ultra-professional Nazi-backed German racing outfits, this was Britain at its amateur best.

After its Le Mans debut, the car was entered for the following August Bank Holiday Brooklands race meeting, the last ever at the track. Driven by Lord Selsdon and now numbered 5, it crossed the line in second place.

Lord Selsdon clearly was bitten by the racing bug, for he returned for the first post-war Le Mans in 1949, and won it with a brand-new Italian manufacturer by the name of Ferrari – whatever happened to them?