The Phase 4 story is probably the most celebrated story in GT-HO folklore. The new XA GT model had been released in 1972 and a GT-HO Phase 4 model was needed to take over from the XY GT-HO Phase 3 on the race track. Four XAs were built before production was stopped due to a "super car scare": one made it through the production line, and is the only one with an HO compliance plate (it's Calypso Green), and three prototypes were built for Bathurst (they're all Brambles Red).
The Phase 4 was never officially released by Ford Australia. Three of those four still exist today: two are in the video link below (two of the three racers), and pictures of the production model are in the third link below.
Ford Falcon GT-HO Phase 4 Videos of two of those three The Calypso Green Phase 4 World's Fastest Four Door The Car That Never Was The Final Finest Phase
In March 2007 a Phase 3 (there were 300 built) was sold for $683,500 and a few months later in June, a Phase 3 sold for $750,000. In June 2018 the first-ever million dollar sale arrived, when a Phase 3 was sold for $1,030,000. Four months later, in October 2018, the two million dollar barrier was breached when one of the three surviving Phase 4s was sold for an eye-watering $2,100,000.
GT-HO Phase 3 sells for a bucket-load
This Phase 3 sells for a truck-load
Paul Carthew Phase 3
The Million Dollar Phase 3
The Two Million Dollar Phase 4
Other Ford Vehicles
History of the Falcon GT
Ford Mustang in "Bullitt" (1968)