The 500cc race that Stirling had entered his #5 Cooper-JAP 500 Mk.II in preceded the first ever British Grand Prix held at Silverstone on 2nd October 1948, won that year by Italian Luigi Villoresi in a Maserati 4CLT/48, and often cited as the first British Grand Prix of the modern era.

The race meeting marked the opening of the Silverstone Circuit, although at the time the site was only on a one-year loan to the RAC from the Air Ministry, having been a bomber station during World War II from which Vickers Wellingtons operated. The Grand Prix and the 500cc race ran on a 3.67 mile circuit which utlised the main runways and perimeter roads of the airfield, and looked very different to the modern circuit of today.

"I was just a teenager at the time, so it was such an exciting experience to be at a circuit like that," said Stirling of his first at Silverstone.

"It was what it was - an aerodrome and the pits, for what they were at the time, were made from corrugated iron.

"It was all rather crude, oil drums cut off perimeter roads to stop us getting lost, but anything we could race on we were grateful for. Still, there was something special about it even then."

Much as they do today, spectators camped in neighbouring fields but when it came to the race itself, they could effectively position themselves where they liked.

There were no stands, or even raised embankments, so people would drive their own cars close to the circuit and then line the edge of track with, at most, a few bales of hay separating them from the racing cars.

"Even though there were no stands like you see today, there was a really big crowd there which one was not used to seeing at that point, but there was a lot of excitement about it because there were so few places in England you could race like you could at Silverstone." as Stirling recalled.

The 500cc race was dominated by privateer Cooper entries that included Stirling as well as John Cooper himself, both driving his new Mk.II. Future four-time British Hill Climb Champion Ken Wharton was also in the running, driving his self-built 500cc special, in a strong field of well over 30 cars, which saw Stirling qualify on the front row of the grid.

Despite the prestigious occasion, running two hours before the main Grand Prix event, the 500 cc race was actually the first ever competitive race held on the Silverstone Circuit, the start was something of a shambles. When British Racing Drivers' Club President Lord Howe dropped the starting flag only two of the 34 drivers were ready to begin. Eric Brandon, an experienced 500cc driver, and the first to win a 500cc race in Britain, was not even seated in his car.

At the end of the first lap, Stirling led Colin Strang, R M 'Curly' Dryden and John Cooper. After three laps of the thirteen lap race, he was just under a second in front of Spike Rhiando, again racing a Cooper JAP 500 Mk.II.

Out at the back of the circuit, an engine drive sprocket worked loose, bringing Stirling's car to a halt. He had to run back to the pits to get the tools necessary to repair it and then run back to the car again, only to retire it from the race with no drive. 

Spike Rhiando won the race from John Cooper in second, and the 58 year-old Baronet of Bodicote, Sir Francis Samuelson, also racing a Cooper Mk.II, in third place. Brandon recovered from the shambolic start to finish in fifth place.

Happily Stirling was to have better luck in the 1949 500cc race, again held ahead of the British Grand Prix, this time leading from start to finish and winning the race.