That included the GT3 car and the Gen3-spec Supercar that will take on the Camaro when the new rules are introduced next season.
While the public has seen a Gen3 Mustang before, the prototype has been running the sixth-generation body panels throughout the development process.
It's only now that it can be updated to the new shape, with Ford confirming that homologation team Dick Johnson Racing is currently switching the bodywork from S550 to S650.
The prototype will make its public debut in S650 form at the Bathurst 1000 early next month.
“We can say it will be at Bathurst, the Mustang, which is very exciting," said Ford Performance boss Mark Rushbrook.
“DJR – and we work closely with all our teams – but certainly DJR is the homologation team, they have been very close with the [Ford Performance] aero development with the body part design.
"The transformation of the car is well underway and on schedule for Bathurst."
While what will appear at Bathurst will be representative of the S650 Mustang Supercar it may not be the absolute final spec of the bodywork.
The car will still need to be subject to the VCAT aerodynamic testing for the shape to the signed off for homologation by the series.
“With VCAT still pending, it’s as final as it can be at this point, subject to any modifications in that VCAT," confirmed Rushbrook.
The Bathurst unveiling of the Supercar will mark the first time the seventh-generation Mustang has been physically seen anywhere in the world.
The Bathurst 1000 will take place on October 6-9.
