Daniel Ricciardo was disqualified from second place after Formula 1's first race with V6 hybrid cars – the 2014 Australian Grand Prix – within six hours of the chequered flag.
Federation Internationale de l'Automobile (FIA) stewards found the Renault power unit in Ricciardo's Red Bull Racing RB10 had pumped fuel faster than the allowed 100kg per hour.
Now, after more than six months of investigation, the same FIA won't say what it found regarding the fuel flow of last year's Ferraris.
The SF90s of Charles Leclerc and Sebastian Vettel had enormous straight-line speed for most of the second half of last season - especially noticeable in qualifying – and rival teams figured Ferrari had found a way to tamper with the mandatory fuel-flow meter to get around the 100kg/hour regulation.
None of the other nine teams officially protested, but Red Bull's young superstar driver Max Verstappen blurted on Dutch TV about Ferrari "cheating".
After six straight pole positions by the scarlet cars, three of which were converted to race victories – at Belgium's Spa, most importantly (for Ferrari) Italy's Monza, and on the streets of Singapore – the FIA issued teams a technical clarification at the third-last GP of the year in the US, in response to a series of questions from Red Bull Racing, which Ricciardo had departed at the end of 2018 for Renault's factory team.
Ferrari's run of pole positions suddenly stopped, and its only podium in the last three GPs was Leclerc's distant third at the final race in Abu Dhabi.
The F1 cars for the season starting in Melbourne on Friday week have just completed six days of testing in Spain.
Twelve minutes before the end of that testing the FIA issued a statement saying that, after a "thorough technical investigation" of the SF90s, it had "reached a settlement" with Ferrari that supposedly will be for the good of all F1 teams and motorsport generally.
"The specifics of the agreement remain between the parties," said the FIA, not entertaining any questions about it.
Ferrari isn't commenting either, although team principal Mattia Binotto claimed late last year that the SF90's improved straight-line speed had come from finding more downforce.
"The FIA and Scuderia Ferrari have agreed to a number of technical commitments that will improve the monitoring of all Formula 1 power units for the forthcoming championship seasons as well as assist the FIA in other regulatory duties in Formula 1 and in its research activities on carbon emissions and sustainable fuels," Friday evening's FIA statement said.
While the other teams haven't commented publicly, the issue could erupt - more so than Mercedes-Benz's dual-axis steering system or Racing Point copying last year's Mercedes W10 - on the eve of the Australian GP.
Ferrari's rivals, which often joke that FIA stands for Ferrari International Assistance, are reported by the BBC's chief F1 writer Andrew Benson to be "shocked" and "angry".
"Teams believe fundamental questions are raised by the way the FIA has chosen to end the Ferrari investigation," Benson has written.
"Does the lack of punitive action against Ferrari mean that the car was legal at all times in 2019?
"If so, why not say so? Why the need for a 'settlement', and what was that settlement?
"What confidence can teams have in F1 if the FIA is not able to conclude a technical investigation without saying whether the car in question was legal or not?"
If Leclerc's Ferrari had been found to be illegal and disqualified after his victory in Italy, Ricciardo would have had – admittedly after the podium presentation – his first and only top-three result with Renault, having crossed the finish line fourth at Monza.
For the season about to begin, the FIA has introduced a second fuel-flow sensor.
Daniel Ricciardo was "pretty happy" to wrap up pre-season testing with Renault third fastest – on the softest of the tyre compounds from Pirelli.
"Testing has been positive for us," carsales.com.au global ambassador Ricciardo said.
"We've improved the balance of the [RS20] car, worked through some set-up changes and our reliability has been strong."
However, there were signs from the testing that Renault – the sport's No.4 team in 2018 and No.5 last year – could be behind Mercedes, Red Bull, Ferrari, Racing Point and McLaren when the real action starts in Melbourne.
Ricciardo will scale back his promotional and media activities to avoid a repeat of last year's AGP, when he felt his performance – running wide at the start and damaging the nose of his car, putting him out of contention for championship points – suffered from trying to please too many people in the lead-up.
"I will do less this year ... just try to do enough that I'm treated like every other driver that week – and hopefully get the season started in the points," he said.
The only slight question mark over top team Mercedes is the reliability of the power unit in its W11, while all teams are on edge about what the coronavirus could mean in terms of crews getting to the first three GPs, with Bahrain and the new Vietnam race hot on the heels of Melbourne.
The career of British-based Melbourne teenager Oscar Piastri – one of four Australians in this year's Formula 3 Championship in Europe – is to be managed by Mark Webber and his wife Ann.
Piastri, 18, won last year's Formula Renault Eurocup and, while still completing his schooling in Hertfordshire, is in Renault's junior academy that is trying to produce future F1 drivers.
"We think Oscar can do great things," Webber said, while Piastri is hoping the nine-time GP winner "steers me in the right direction and to the right people in the paddock".
F3 testing is on now in Bahrain, with Piastri driving for Prema Racing, Jack Doohan for HWA RaceLab with Red Bull backing, Tasmanian Alex Peroni for Campos Racing after recovering from the back injury suffered in last year's massive crash at Monza, and West Australian Calan Williams with Jenzer Motorsport.
Another Webber protege, New Zealander Mitch Evans, has lost the lead of the Formula E electric open-wheeler series despite a blistering drive in his Jaguar from the back of the field to sixth in Marrakesh, Morocco, at the weekend.
Portugal's Antonio Felix da Costa took the series lead with his win for DS Techeetah, the team that is Chinese-owned, associated with Citroen's premium brand (DS) and run by Australian Mark Preston.
DS Techeetah's reigning champion, Frenchman Jean-Eric Vergne, was third in Marrakesh, behind German Max Guenther driving for BMW i Andretti – da Costa's former team.
Evans remains second on the driver points table with 56 to da Costa's 67, with BMW's Brit Alex Sims and Guenther on 46 and 44 respectively.
Pure ETCR is a proposed new European electric, rear-wheel-drive touring car series to which Hyundai, Alfa Romeo and Spain's Cupra are committed.
"Formula E promotes technology, it does not promote products," said Francois Ribeiro, head of Eurosports Events which will run Pure ETCR.
"Touring cars have always been a great tool for manufacturers to promote their product.
"We [will] promote real cars, not single-seaters, not electric SUVs."
The cars will run a standardised Williams Advanced Engineering powertrain capable of 680hp.
Between sessions the cars will charge in a central energy station in front of fans and the paddock will be powered by hydrogen generators.
The first sighting of the cars will be in a time trial at Britain's Goodwood Festival of Speed in mid-July.
Four Australians – if we claim 'The Giz' – will be racing at the 24 Hours of Le Mans in June.
Apart from Porsche factory GT driver Matt Campbell, Shane Van Gisbergen will be in an LMP2 Ligier for Eurasia Motorsports, James Allen – who has TCR Australia and even IndyCar prospects – will be in another LMP2, and Tim Slade a Ferrari 488 GTE EVO.
The French classic has a full 62-car field, with six LMP1s, 24 LMP2s, 11 GTE Pro and 20 GTE Am entries, a special 'Garage 56' innovation entry and 10 reserves.