There is a tense holding pattern in the Supercars paddock this evening as the deadlock over parity continues.
The Ford teams have arrived at Mount Panorama armed with parts that can be fitted to the existing front bar of the Mustang.
It is argued by Ford that the changes would shift the aero balance and reduce drag, two key areas of concern for the Ford teams heading into the Bathurst 1000.
However, with practice less than 24 hours away, hopes of the changes being approved are rapidly fading among the Ford teams.
While there is still no official word on the changes being rejected, the battle now appears to be increasingly uphill for Ford.
It is known that the GM teams are fiercely opposed to any more changes being made to the Mustang before proper wind tunnel testing takes place.
And that opposition is critical to the outcome of this latest push for changes, given they would fall outside an official parity review.
According to informed sources that means at least a majority, if not the entirety, of the Chevrolet teams would need to agree to the changes for Supercars to be able to approve them within its own rules.
Meetings between Supercars and GM personnel and Supercars and Ford personnel have been taking place throughout today.
It now appears likely that the outcome of those meetings will be the rejection of the changes, although crisis meetings are continuing as Ford makes its last-ditch effort to get the changes across the line.
The standoff has created a tense atmosphere in the paddock with speculation of various outcomes going as far as a boycott from the Ford teams.
That is problematic, however, given the terms of the Teams Racing Charter and the obligation to race.