It has effectively been a re-run of the Vehicle Control Aerodynamic Testing (VCAT) process, designed to approve and homologate bodywork, that first took place last November.
The second VCAT came at the request of Ford which has held concerns over aero parity between the new Gen3 Mustang and Camaro for some time.
The test, overseen by Supercars board member Mark Skaife, was expected to wrap up this evening.
According to informed sources, this latest VCAT has yielded significant progress in the equalisation of the aero packages on each of the Gen3 cars.
However that's not to say complete parity has been reached at this point, with question marks remaining over engine performance.
The new, production-based V8 engines have been another area of concern for Ford and its teams as Supercars looks to paritise the 5.4-litre quadcam motor in the Mustangs against the 5.7-litre pushrod unit used in the Camaros.
Ford teams that ran at Winton on Wednesday are understood to have used a revised mapping which solved a throttle response issue experienced by some drivers at the Sydney Motorsport Park test last week.
However there is still a sense from the Blue Oval side that the Chevrolet has a performance advantage, even after a longer shift cut was mapped in to the LTR unit at SMP.
Track action for the season-opening Newcastle 500 kicks off with practice next Friday, with all teams having now exhausted their pre-season testing allocation.
