The weather was similarly fickle across the four-hour afternoon session, with occasional rain shower interrupting the dry running.
Still the times ended up slightly faster overall, Heimgartner repeating his session-topping antics with a 1m29.678s.
As was the case in the morning Will Brown was second fastest, although this time the Erebus driver was only 0.01s adrift as he too cracked a mid-1m29s.
Brodie Kostecki was third fastest while Macauley Jones, Jack Smith and Bryce Fullwood all banked late laps to make it an all-BJR/Erebus top six.
A number of those laps came during an additional 15 minutes of running added to the cut-off after Nick Percat stopped with a loose wheel inside the last 10 of the scheduled minutes.
Another to improve during the extra time was Shane van Gisbergen, who made his first appearance near the top of the times with the seventh best lap.
At that point it was all Camaros in the top 10, although a last ditch effort from Todd Hazelwood in the Blanchard Racing Team Mustang saw him grab ninth, between Mark Winterbottom and Broc Feeney.
The next-best Mustang was was Chaz Mostert way down in 11th in his Walkinshaw Andretti United Ford.
The dominant showing from the Camaro comes amid parity complaints from Ford and head of a fresh VCAT aero homologation test next week.
The end of the official test means that the teams that have exhausted their pre-season allocation won't run again until practice for the Newcastle 500 in early March.
Teams such was WAU, Triple Eight, Dick Johnson Racing and Team 18 still have a day left that will be used next week.
