At its debut in the Monza 1000km in May 2004, the Nasamax finished a remarkable eighth, and at Le Mans the following month it was the fastest car of all in a straight line, clocking over 200mph, and it reached 11th position before gearshift problems, punctures and a misfire (which wasn’t caused by the fuel) dropped it to 47th for a while, before it climbed back to finish it 17th place.

That made it the first ever car to finish Le Mans using a wholly-renewable fuel source. And yet it had built on a tiny budget, adapted to suit the then-new aerodynamics regulations and hamstrung by the 40kg extra weight of fuel that it was allowed to carry to compensate for the reduced thermal efficiency of bio-ethanol compared with high-octane race fuel.

There was another disadvantage to the fuel too: it emitted strong-smelling fumes. Johnny Herbert, racing the Audi R8 that finished second that year, recalls having to get by the Nasamax quickly because of the fumes. Robbie Stirling, who still owns the Nasamax, laughs that, “They worked really hard to get by you, then you go past them [on the straight] – gassing them at the same time!

“I remember passing everything, it was the fastest on the straight – 330km/h on the Hunaudieres and I’m sure I saw 346km/h on the dash at one point.’

It was ungainly in the corners though, due to that extra weight. “At the Monza start I was first away, says Robbie. I got to the curve and went straight over the kerb, I just had nowhere to go.”

“The 120-litre fuel tank was a big problem,” confirms John Judd, who supplied the specially adapted Nasamax DM139’s 5-litre Judd V10 Series 1.

After a freak accident in the 2004 1000km of Spa when driver Romain Dumas snagged his racing boot on an over-long bolt in the cockpit, preventing him from lifting off the accelerator, the Nasamax was retired, and later mothballed when FIA regulations left it without a series to race in. But then, in 2017, the Masters Historic Racing series reviewed its regulations to allow a wider range of cars to enter – and the Nasamax once again had a home.

Some changes were needed, not least updating the engine to the 5.5-litre Judd V10 Series 2. The work was carried out by KW Special Projects, led by Kieron Salter – the former Reynard designer and engineer who had worked on the Nasamax in the early 2000s…

“Nasamax really was a bootstring project,” says Kieron, “but it was way ahead of its time and got a lot of press at that time.”

Now there are plans afoot to not only let the rebuilt and restored Nasamax loose on the track again but to replicate the original Nasamax to produce further cars. Bio-ethanol fuel never received the development it deserved, and electric cars have overtaken them – but surely there’s a place for a green racer in historics?