The odd mix of inertia and razzmatazz of the Month of May at Indianapolis did not sit well with Clark initially. He found its graded rookie tests demeaning and tiresome, the press interest bullish and intrusive. But he warmed to them. Indeed his car would soon sport a bold central yellow stripe; his new American overalls were primrose with powder blue stripes along their arms; and for a brief time his new American crash helmet was silver.

The money helped: Clark was set to earn more in a single day than he might in the rest of the season. What mattered most, however, was his silencing and then winning over of the ‘Not in my Brickyard!’ disbelievers through overwhelming brilliance and understated charm. America and Clark were good for one another.

He might have won on the occasion of his Indy 500 debut – he finished second having led 28 laps in 1963 – had he been more attuned to the possible advantages to be gained under the yellow flag – and had not leader Parnelli Jones been dropping oil onto an already greasy track. The latter controversy would cause the victorious Jones to come to blows with mouthy rival Eddie Sachs the following day. Clark, in contrast, smiled a genuine smile and shook the winner’s hand. He knew that the technical tide was with him.

The rightness of the Lotus rear-engined way was proved in August when he led all 200 laps, from pole, at the Milwaukee Mile; he even backed off so as not to cause offence by lapping runner-up and title favourite AJ Foyt. He led the first 49 laps at Trenton, New Jersey, in September, too, only for an oil pipe to break.

His 1964 Indy, however, would be a disaster caused by Chapman’s decision to run on Dunlops rather than proven Firestones. ‘Sticky’ rubber had helped Clark to take pole but a blowout wrecked his left-rear suspension when leading just before quarter-distance.

Lessons learned, this combo dominated in 1965, Clark starting second and leading 190 laps – a mark bettered by only two winners since 1911 – on his way to victory; a masterclass, well worth missing the Monaco GP – his jinx race – for.

He was by now hugely popular in America – despite his being the extinction event for its beloved Roadster ‘dinosaurs’ and driving a car carrying a supposedly unlucky colour. That his Lotus at Indy in 1966 was in the Day-Glo of sponsor/team associate Andy Granatelli’s STP concern was indicative of Clark’s changing world: in order not to be taxed more than he was actually earning – the Inland Revenue had got wind of Indy – he had grudgingly relocated to The Bahamas.

What hadn’t changed was the attitude that so impressed the Americans. While sitting out the two hours required to clear up after the horrendous accident that claimed the lives of Sachs and Dave MacDonald in 1964, Clark had soothed agitated crew members – and perhaps himself – by telling them not to worry: ‘It’s only sport.’ The nervy young racing driver so spooked by Spa in 1958 was much-changed.

At that 1966 Indy, another 500 blighted by a (thankfully much less injurious) pile-up, Clark joked that ‘Spinning Takes Practice’ – STP – after twice somehow keeping his car out of the wall. That race would also end in controversy – Clark was eventually classified second behind the Lola of rookie Hill after a lap-charting snafu – but again he let others do the arguing.

Those Bahamas proved a bore – boxes lay unpacked in his condo – and this reluctant tax exile chafed at being denied chances to perform in the UK. He was, however, free – far from Chapman’s control – and willing to take up intriguing offers from the States. He drove a NASCAR Ford for Holman-Moody in the American 500 at North Carolina’s Rockingham in October 1967 – he was running 12th when the engine let go – and the following month raced a single-seater Vollstedt at Riverside’s Rex Mays 300: he qualified second and had just grabbed the lead when he missed a shift and tagged a valve.

Chapman (and Duckworth) had handed him that season’s fastest F1 car, but Clark’s few but pertinent extracurricular activities caused him to consider if the high priest of racing car design was fallible and had perhaps missed an aero trick or two spotted by others.

The wedge-shaped, four-wheel-drive turbine Lotus Indycar of 1968 probably eased those worries. The previous Indy had been a bust in dated equipment – Chapman had taken his eye off the ball – but Clark was convinced after his initial testing in March 1968 of this remarkable new car that he had driven another winner…

When news of his fatal crash reached the USA, an LA disc jockey told those mourning the passing of this great driver to put on their headlights. The freeway lit up. It was midday.