Actually, I have a new theory on a RWD Colaboration.
1. Orion Falcon could donates its top hat and chassis from the firewall back.
2. All in front of the firewall is unique to Australia and fitting the Inline 6.
3. FNA uses Mustang firewall, front, running gear, electrical systems and new front sheetmetal.
4. In 2010 Australia drops Inline 6 and switches to FNA adaptation.
They could also do the same thing with either Fusion (same tread width) or Taurus.