Sebastian, my hero in Let’s Misbehave drives a Bentley Speed Six. This British car, designed by WO (Walter) Bentley himself, was produced between 1928 and 1930. It became Bentley’s most successful race car, winning the 24 hour Le Mans in both 1929 and 1930, but it also came fitted as an everyday street vehicle.

The car may seem big and bulky to the modern eye, but in its day it was as sleek as they come. Powered by a 6-cylinder engine, these were high performance vehicles. Only 182 were made but it is a testament to the quality of the car that many still survive today. Most of the survivors are in British racing green, that distinctive colour worn by all British race cars in those glorious days when national pride still reigned supreme and advertising sponsors did not get to dictate the vehicles’ liveries. But these were also the days when most cars were bespoke: customised for their owners. Sebastian’s choice of colour was bright yellow, as fashionable back then as it is rare today.

An unlikely choice for the staid Sebastian, it’s a glimpse of his Speed Six that makes my heroine Gabrielle begin to wonder what depths this seemingly quiet and conservative man might hide.

What particularly interested me, as a South African, was uncovering a link between Bentley and famous South African mining magnate Barney Barnato. Barney’s son and heir, Woolf Barnato, became Bentley’s financier during the 1920s and was also one of the ‘Bentley Boys’, a group of independently wealthy young Brits who raced the Bentley cars in those glorious days of thrills and spills.

Forget Top Gear. These guys were the originals. The Speed Six earned the nickname ‘Blue Train Bentley’ after Barnato raced Le Train Bleu from Paris to London in 1930. The Bentley won, though Barnato barely avoided arrest in France for racing in the streets. For more of this story, click here.

Sadly, Bentley Motors was badly affected by the Wall Street Crash of 1929 and they were forced to sell out to rival manufacturer Rolls Royce. Happily for motoring history the name Bentley survived, though I suspect few people these days would equate the dignified Bentley saloons with the dashing race cars of the 20s.

And here are a few more bits of useless but fascinating trivia for you to stun people with at dinner parties:

  • The chassis was made of steel, but the car’s frame was wood covered in fabric.
  • The racing version weighed in at two and a half tons. A far cry from today’s carbon fibre F1s.
  • Western Australia’s CID imported two Speed Sixes to use as police cars. They were known as the Bentley Patrol.
  • Jay Leno has a silver 1929 one-seater racing model
  • A 1930 Speed Six sold for £2.8m at auction in 2004