which car/model changed the face of performance for aussie cars?

[Falc'man]

I agree with Hulk.
As much as I'd hate to admit I think it was Holden's decision to import the LS motors which forced Ford into getting their act together. At least in modern times.
Yes, originally the XR GT started it all, but I think it was the LS motors which re-ignited the battle in most recent times.
The 5.6 Tickfords were awesome and did us very proud, and gave the LS' a hard time and some fat lips and black eyes. I'd take one of those over just about any car out there today. But, again, had it not been for the LS' I'm not sure Ford would have acted.

Now, most would agree, Ford/FPV have shown some initiative by moving the goalposts with Miami. HSV will need to react. And they will. They won't lie down to FPV, they've too much pride to lie down. You must recognise that this modern day rivalry where we're getting north of 450hp came about thanks to Holden/HSV being so dominant with VTII. Ford didn't look at their performance heritage of the 60's and 7-'s to give us what they have in the last 10-15 years and ultimately a blown 5.0 - they were reacting to Holden.