Mercedes Formula 1 technical director James Allison doesn't believe the FIA thought the team could make its Dual-Axis Steering (DAS) device legal after the concept was initially rejected.
Mercedes created a stir at Barcelona testing earlier this year when onboard TV images showed the drivers moving the W11's steering wheel back and forth, and the front wheels responding.
Rival teams questioned the legality of what the team called DAS, but the FIA confirmed that the system had been assessed and approved.
Allison says the team planned to run DAS in 2019 using a lever system on the steering wheel, but the FIA turned down that arrangement, and suggested that the whole wheel would have to move.
"It was really quite difficult indeed," he said in a Mercedes video on DAS.
"And in fact we first wanted to introduce this in 2019.
"We took our ideas to the FIA, showed them, explained why we thought it was legal. And they begrudgingly agreed that dual-axis steering was actually legal.
"But they didn't much like the way we'd done it, because the second axis we were getting from a lever on the wheel, rather than that whole wheel movement.
"And so they said, 'No, you're going to have to move the whole wheel in and out.'
"And I think when they said that they were hoping that would be too difficult, and we would go away and cause them no more problems!"
Mercedes agreed to a ban on DAS coming into force next year in a bid to stop a spending war erupting over it, but Allison still believes it was worth the team devoting its resources to developing the concept.
"We have a very inventive chief designer, John Owen, and he took one look at that challenge - he's got a really, really good gut feel for whether something is doable or not, and that's a really helpful characteristic, because it allows us to be quite brave spending money when most people would feel the outcome was quite uncertain," he added.
"John has a good feel for whether he's going to be able to get out of the woods, and into fair ground again.
"John took that challenge on, reckoned he could do it, put it out to our very talented group of mechanical designers, and between them they cooked up two or three ways in which it might be done.
"We picked the most likely of those three, and about a year after that out popped the DAS system that you saw at the beginning of this season."