Since 1985 the streets of Adelaide have seen some extraordinary days in Formula 1 and V8 Supercars, but none as remarkable as what happened one Sunday in 2016.

The city had a deluge; in fact, two deluges, so big as to red-flag the 250km race twice and, at one point, flooding pitlane so badly that half the garages lost electricity. That forced engineers to plot the progress of their $400,000 race cars and track the incoming weather by peering at their cellphones, praying that their batteries would last.

What emerged from this chaos, of course, was a fairytale. Nick Percat had won before – on debut, at Bathurst, as a co-driver five years before. But that was with the crack Holden Racing Team and the team he now drove for, LD Motorsport, was the lowest-funded in the pitlane. The car was second-hand, the budget modest, and Percat started the race from 15th on the grid. But then it rained – and team manager Barry Hay had read the rule book.

After the race resumed for the second time many teams came a terrible realization; the rule requiring them to put a minimum amount of fuel in the cars during the pitstops stayed in place despite, inevitably, a shortened race. As drivers one by one peeled into the pitlane to take on fuel they didn’t otherwise need, Percat’s Holden Commodore took the lead. He had pitted for enough fuel and he stayed there – and won.

The crowd went mad, for good reason. Percat was an Adelaide local; better yet, his father worked at Holden’s assembly plant in the suburb of Elizabeth. The win was especially sweet for car owner Lucas Dumbrell, who had been a promising driver himself until a crash in an open-wheeler confined him to a wheelchair.

For once, the Holden vs Ford rivalry was set aside to celebrate a great day. But, just for once.

The contest between Australia’s two main automotive brands has been more than the cornerstone of motor racing down under for 50 years. It has been a part of the fabric of Aussie life. For generations most families had either a Holden or a Ford in their driveways, and even the ones who did not supported one brand or another.

And now, Holden is departing, not just motor racing but the automotive marketplace.

This is not like Pontiac’s exit from NASCAR in 2004. It’s not like any IndyCar team departing the series – or even the Penskes failing to qualify for the Indy 500 in ’95.

To Australians, Holden is bigger than that. Not having Holdens on the track or in the showrooms would be like the Dallas Cowboys quitting football. Or the New York Yankees moving to Athens – the one in Greece, not the one in Georgia.

Motor racing in Australia is popular because of the Holden vs Ford rivalry. In the 1960s, Touring Car racing was dominated by, mainly, monied car dealers importing fast cars to race – firstly Jaguars, then Ford Mustangs. Then along came a Canadian, Allan Moffat, with a TransAm Mustang that had been gifted to him by Ford HQ in Detroit. He was not interested in retailing cars; he want to race them as a professional racing driver, and the game was about to change.

Moffat raced the car everywhere he could. At the same time, Ford Australia increased its commitment to Production Car racing’s biggest event, the Bathurst 500, with the bespectacled Moffat as its lead driver. In a locally-developed four-door Ford Falcon, he won two 500s in a row, and Holden needed to strike back.

In 1972, it did. A dark-haired youngster from Melbourne drove through a storm, solo, to win his first major race. He was Peter Brock – good-looking, charismatic and as fast as lightning. He had put Holden on top, and Australian motor racing had its greatest rivalry.

Behind the scenes, the rivals actually admired each other, but they knew how to play the game. Their teams signed with different oil and tire sponsors; they even flew on rival airlines. The crowds fell into line; if you were a Holden fan, you backed Brock (and some of the other Holden men); on the Ford side, it was the same – Moffat and his Ford offsiders, or nothing at all.

In 1977, the earth shook. Colin Bond, who had been Brock’s teammate (and who himself won at Bathurst in 1969) jumped the fence and switched, to become Moffat’s backup. Drivers had changed brands before, but this was a high-profile winner – and worse, when he backed up Moffat to a crushing 1-2 finish at Bathurst, Holden was humiliated.

Holden fought back. Ford exited, leaving Moffat to struggle on with a few privateer entries before he switched brands, to Mazda, to race an RX-7. Brock and Holden needed a new rival and they got one, in the form of slow talking but fast thinking Dick Johnson, who had built a V8 Ford Falcon racer in his workshop and took it to Bathurst.

He was thrashing the best in the country in the race, Brock included, when the unthinkable happened. Johnson hit a rock that had been dislodged from a slope next to the track. In an instant, his winning hopes and his car were destroyed.

Mid-way through a TV interview with visiting commentator Chris Ekonomaki, Johnson broke down. In response, the host broadcasters’ affiliates around the country had their switchboards light up, viewers pledging money to help get his team back for future races. Ekonomaki was not the only American visiting the race; Edsel Ford was there as well, and on the spot, he pledged to match any public donations dollar for dollar.

Johnson was back in business, and Ford was back in Touring Car racing, which would have come as a hell of a shock to those running the Australian arm of the company.

So was set up a golden era; Holden and Brock versus Ford and Johnson. Such was their impact of their battles is that their influence is still felt in the sport today. Johnson remains a minority owner in his own team, having sold a major stake to Roger Penske, and a motorsport industry has grown up in the Brisbane/Gold Coast corridor around his original base.

Brock’s team was based in Melbourne, which has become the sport’s other motor racing hub. In the late 1980s he split with Holden, for which he built high-performance road cars. When Holden Special Vehicles and the works-backed Holden Racing Team grew out of those ashes, the make’s successes on-track continued, especially when what is now Supercars emerged in the 1990s.

Along the way teams and even brands came and went, but Holden stayed. Its winning drivers, Craig Lowndes, Mark Skaife and Jamie Whincup, became household names, and in spite of the entry and exit of makes such as Nissan and Volvo (and a privateer, customer-based Mercedes-Benz team), they have remained at the core of Supercars racing.

But if the fans loved what was happening on the track, they did not back it up with their purchasing habits. Whereas Commodore and Falcon once dominated the marketplace, as they have in other markets Australian families migrated away from large four-door sedans and station wagons toward SUVs and four-door pickups.

Sales of the Australian-built road cars on which the race cars were based were plummeted, and with the government’s enthusiasm for financially supporting a declining industry waning, the inevitable happened. In 2017 Ford, Toyota and Holden all stopped building cars in Australia. In an import-only model, Toyota thrived; Ford held firm but sales of Holdens plummeted.

Roland Dane, boss the works-backed Red Bull HRT, which has an ongoing deal with Holden until the end of 2021, summed it up.

“Unfortunately one of the issues is that many of the people that have been barracking [rooting] for the Holden brand over the last 10 years or so haven’t actually been buying the product, for whatever reason,” he said. “It’s a fact of life that people have been turning up to watch the races in other brands.

“It’s something we’re all aware of. Times change, and we have to change with them.”

So did the Walkinshaw Andretti United team, which formerly held works status with Holden:

“It’s very sad to see them leave. We are thankful for their support, and proud of what we have achieved together, including seven Bathurst 1000 victories, and six driver championships. Our team and supporters have bled red for a long time, the lion and helmet [logo] will live on in our team’s history forever.”

Ironically, the Holden news came in the same week that the 2020 Supercars Championship Series starts in Adelaide. For the first time since 2012 there will be no other brands on the 24-car grid, made up of 16 Holden Commodores and eight Ford Mustangs.

The questions the Holden teams face is, what will they do next? It is likely that in a year’s time, with every Holden dealership in Australia and New Zealand closed, most of them will still race their current Commodores, as it will be virtually impossible to change, particularly since new regulations are due to take effect for the 2022 season.

Nissan officially withdrew from the sport at the end of 2018 but its team, Kelly Racing, continued to race its Altimas last season, until switching to Fords for 2020. That can happen with the current Commodores, says Dane.

“The homologation from Supercars will be valid for several more years, as it always is,” he said. “If you remember with the [Ford] Falcon, even after they stopped production of the car and its availability to the public it carried on racing for several years.”

And it appears that brand loyalty will continue, even if Holden itself does not. As the cars took to the track in Adelaide this week there was no sign that any of the Holden fans were lacking the passion they have show for the brand over a long time. Holden owners are like that, right around the world.

Even Dale Earnhardt Jr, a man who has driven a Commodore V8 Supercar and is a proud owner of a Holden-rebadged car himself, has a heavy heart.

“Sad to see this happen,” Junior said on social media. “I really loved this brand and even how Australia approaches the automobile in general. I own a converted Pontiac G8 that’s now a Commodore. Was wondering if I should sell it one day. Nope, don’t think I will.”

In Australia, many people feel the same way. They will hang on to their beloved Holdens, and probably continue to watch Supercars races, particularly Bathurst, regardless of whether it it contested by Commodores, Camaros or something else.

That’s the pity. The passion continues. It’s just too bad Holden didn’t offer their fans cars they wanted to buy.