Dean Fiore was fastest of the additional drivers in Michael Caruso's Nissan during the first practice session of the Coates Hire Ipswich SuperSprint.
The half-hour session is just one of just two exclusive sessions for additional drivers prior to the PIRTEK Enduro Cup, allowing the drivers some extra miles on track before the prestigious long distance races.
Twenty-three of the 25 cars were out on track for the additional drivers session at Queensland Raceway, with Lee Holdsworth and Scott McLaughlin's V8 Supercars the only cars off-track as they await international co-drivers' arrivals in Australia.
Lucas Dumbrell Motorsport ran ex-full timer Karl Reindler in Nick Percat's car in the absence of Oliver Gavin, and Dunlop Series driver Aaren Russell in Tim Blanchard's car as a co-driver has not been signed for the #23.
It was tight between the top drivers, with Fiore just 0.17sec ahead of Dean Canto in David Reynolds' Bottle-O Falcon with his 1min10.4910 lap, though the Falcon ran a soft Dunlop tyre in the session.
Steve Owen in Mark Winterbottom's car was third, with another Nissan fourth, with David Russell in the Jack Daniel's Nissan.
Returning champion Marcos Ambrose managed eighth against the other additional drivers, ahead of Steven Richards and Taz Douglas to crack the top 10.
"It feels really good," Ambrose said.
"Like everybody, we're running around on pretty used tyres, but felt pretty good - nice and consistent.
"My area of concern is always brakes with these cars. I got better and better with brakes and tyres got worse and worse ... pretty happy with that session."