The first technical rows of 2014 are well underway.
It had already emerged that the FIA is unhappy with some of the radical nose solutions, with one camp of teams accusing the other of fielding either dangerous designs or too cheekily skirting around the 'spirit' of the rules.
Arguably, however, McLaren's wing-like rear suspension arms are causing the bigger stir.
Italy's Omnicorse claims world champions Red Bull have already sent a request for clarification to the FIA.
But that doesn't mean that, even if the design is ruled categorically legal, the other teams will rush to copy it.
"The design is based upon quite a lot of air resistance (drag); especially the part that bends downward," said Red Bull designer Adrian Newey, according to Germany' s Auto Motor und Sport.
Mercedes' Paddy Lowe, however - a former McLaren man - is not so sure.
"McLaren will have determined that it found a way for it to work without major disadvantages," he predicted.
But Williams' Pat Symonds thinks that because of the way the suspension arms have to bend backwards towards the rear, McLaren will have lost some stiffness benefits.
"They may have compensated with more mass, so I would guess that the wishbones are heavier than normal," he said.
Some have said McLaren will retain its potential 2014 advantage for a long time, because it will be so difficult for rival teams to change entire rear suspension layouts.
Symonds is not so sure of that.
"It just wouldn't be as perfect a system as McLaren's, because they have based the whole concept of the car around it," he said.
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