F1 will begin its new technical era this weekend as the Bahrain Grand Prix offers the first chance for teams to race their overhauled cars.
A concerted effort has been made by F1's rulemakers to reduce the technical freedoms available to teams, pushing to create closer competition while retaining the goal of making it easier for cars to follow so on-track battles are improved.
There were some fears it would result in all the cars looking the same under the new ruleset, but teams and drivers were pleasantly surprised to see so much variation through the launches and in pre-season testing.
One of the biggest areas where teams took different directions was with sidepod design.
Mercedes brought a radical slimline solution to the second test, while Ferrari has a far wider, dipping design.
The FIA's head of single-seater matters, Nikolas Tombazis, explained how his team stayed "very precious about certain areas of the cars" that were the most sensitive aerodynamically in creating dirty air.
It meant that other areas that were less influential, such as the sidepods, could be opened up to allow more variation - but Tombazis conceded he did not expect to see so many differences.
"We did consciously free up the sidepods more than we did other areas," Tombazis said.
"We could easily have written rules for the sidepods that would have been all the same if we wanted to. We didn't do that because we felt it was an opportunity. So in that respect, that wasn't totally random that happened with the sidepods.
"If you asked me whether I expected to see the variety of the solutions that teams produced in the sidepods, then no, that exceeded what I was imagining, I must say."
Mercedes turned heads at the start of the second test in Bahrain when it debuted its radical new design, leading to questions about whether it was within the spirit of the regulations after quotes attributed to Red Bull boss Christian Horner emerged.
But Tombazis said the FIA's mantra of protecting the spirit of the regulations about being able to "react more easily for correcting regulations" and "not so much to go and say a car is illegal or something like that".
"I don't think teams designed a car in any particular way, just because they liked us," Tombazis said.
"They still made what they think is the fastest car and the best interpretation. They worked really hard on the regulations like one would expect them to do.
"I think by and large, the regulations were reasonably well written. Some areas were not perfect, and will be tweaked in the future.
"We still have to follow the governance, the governance has voting and so on. We don't pluck it out of thin air and say here are the new regulations."
