A question mark continues to hang above the legality of the fastest two cars ahead of the 2017 season.
Although the new Mercedes and Red Bull cars are yet to be launched, it is already known that they will feature the same 2016-style suspension concept that some are comparing to outlawed active suspension.
Ferrari have already challenged the concept's legality, and at the latest meeting of F1 technical bosses last week, the matter was discussed at length again.
Yet for now, the FIA is declaring that the system is legal.
Some teams, reportedly led by Ferrari, have argued that Mercedes and Red Bull - or the FIA - should at least explain how the system works, but Auto Motor und Sport reports that "the campaign has been unsuccessful" and the risk of a formal protest in Melbourne remains.
A report in Italy's authoritative La Gazzetta dello Sport agreed: "The meeting last week did not result in an agreement about what is allowed and what is not.
"Many proposals were on the table, but the position of the teams is very far apart."
However, the report says that one possible outcome before the Barcelona test is that Charlie Whiting will issue a new technical directive regarding suspension legality.
