Expect fresh cries over illegal cars after the 'diffuser three' grabbed the top three places on the timesheets in Melbourne's second practice where Nico Rosberg led home Rubens Barrichello and Jarno Trulli.
Report: Jarno Trulli was the first to venture out as the session began, leading a train of driver as they completed their installation laps. The Italian opted to remain out on track, clocking the sessions first lap time, a 1.32.102, but he was quickly overhauled by Timo Glock, Mark Webber, Kazuki Nakajima and Sebastian Vettel.
With 14 drivers out on track the timesheet continued to change with Adrian Sutil putting his Force India up into first place while Fernando Alonso went fourth quickest for Renault. Sutil's reign was short-lived as Heikki Kovalainen went fastest only to lose out to Nico Rosberg.
Alonso, pushing hard, clipped the inside kerb at Turn Five before going into the corner backwards. The Spaniard, though, managed to avoid damaging his Renault R29.
Sutil returned to the front of the pack with a 1.28.111 with Kovalainen slotting into second place, just 0.03s off the pace. Mark Webber put his Red Bull into third place before being dropped by Timo Glock. Hamilton improved to third place while Jenson Button took control of the session, posting a 1:28.002.
Button continued lapping, bettering his time to break into the 1:27s before Jarno Trull overhauled him at the top with a 1:27.168. Kovalainen had an off-track excursion across the grass at Turn One.
With the drivers putting in serious laps the timesheets continued to change with Rosberg, Trulli, Glock, Sebastian Vettel, Sutil, Mark Webber, Felipe Massa and Button completing the top eight after the first half an hour.
Rubens Barrichello moved up to fourth place behind the two Toyotas before struggling to get his Brawn GP car into Turn 1, which resulted in his running wide and skipping across the gravel.
The Renaults continued their struggle from Practice One for pace and grip with Nelson Piquet Jr and Fernando Alonso down in 16th and 17th places. Only the two Toro Rossos and Nick Heidfeld were slower.
Rosberg continued to etch out a lead at the front, posting a 1:26.053 while the Toyotas and Brawn GP cars were far off the pace. At the back of the pack the Toro Rosso drivers improved to 15th and 16th places while Heidfeld moved up to P18 leaving the Renaults at the very back of the field.
Glock and Vettel both ran wide at Turn 3 within seconds off each other with the latter bringing out the yellow flags for the second time today as his Red Bull remained stuck in the gravel.
With half an hour left on the clock the top eight were: Rosberg, Trulli, Barrichello, Webber, Button, Glock, Nakajima and Vettel.
The lap times slowed down in the final third of the session as the drivers concentrated on longer runs, and putting the mileage on their cars.
Ferrari, though, had cause for concern as Kimi Raikkonen, who was one of the quicker drivers in Practice One, was languishing at the bottom of the timesheets with 15 minutes to go. The 2007 Champ finally managed to improve to 14th place but was still over a second off the pace.
Pushing hard for the final few minutes Heidfeld ran wide at Turn 3 and Nakajima and Button almost collided after taking the same line.
And despite all 20 drivers having a go at it Rosberg held onto the P1 slot, finishing the session ahead of Barrichello and Trulli. Meanwhile Ferrari's best-placed driver was Massa in 10th place and McLaren's was Kovalainen in P17.
01. Rosberg Williams 1:26.053 36 laps
02. Barrichello Brawn 1:26.157 38 laps
03. Trulli Toyota 1:26.350 42 laps
04. Webber Red Bull 1:26.370 30 laps
05. Button Brawn 1:26.374 38 laps
06. Glock Toyota 1:26.443 42 laps
07. Nakajima William 1:26.560 33 laps
08. Vettel Red Bull 1:26.740 19 laps
09. Sutil Force India 1:27.040 29 laps
10. Massa Ferrari 1:27.064 35 laps
11. Raikkonen Ferrari 1:27.204 32 laps
12. Alonso Renault 1:27.232 28 laps
13. Fisichella Force India 1:27.282 32 laps
14. Heidfeld BMW 1:27.317 34 laps
15. Kubica BMW 1:27.398 36 laps
16. Bourdais Toro Rosso 1:27.479 36 laps
17. Kovalainen McLaren 1:27.802 35 laps
18. Hamilton McLaren 1:27.81 31 laps
19. Piquet Renault 1:27.828 35 laps
20. Buemi Toro Rosso 1:28.076 33 laps
Source : Planet F1