The Jerez test, which marked the final outing ahead of the new in-season test ban and the start of the 2009 Championship, began on Sunday, lasting until Thursday afternoon. Only four teams, though, opted to run; Brawn GP, Renault, McLaren and Williams.
It was the latter outfit, though, that surprised many when Kazuki Nakajima posted the fastest lap time of the week on Thursday, a 1:17.494.
The Japanese driver's best was almost four tenths up on that set by Brawn GP's Jenson Button on Tuesday while Heikki Kovalainen put in a late charge for McLaren to set the week's third fastest time. He was the only other driver to break into the 1:17s.
Fourth best time for the week belonged to Nico Rosberg, who finished ahead of the Renault duo of Fernando Alonso and Nelson Piquet Jr.
Week's Fastest Times
1 K. Nakajima Williams 1:17.494
2 J. Button Brawn GP 1:17.844
3 H. Kovalainen McLaren 1:17.946
4 N. Rosberg Williams 1:18.07
5 F. Alonso Renault 1:18.343
6 N. Piquet jr. Renault 1:18.382
7 R. Barrichello Brawn GP 1:18.398
8 L. Hamilton McLaren 1:19.121
9 N. Hulkenberg Williams 1:20.013