Jan.11 (GMM) The track debut of Williams' new Toyota-powered car for 2008, the FW30, has been delayed by an extra week.

The car had been scheduled to turn its first laps at Jerez next Monday (14 January), but the German trade journal Auto Motor und Sport reports that Nico Rosberg and Kazuki Nakajima will instead take to the Spanish circuit with the existing 2007 model, the FW29.

"The schedule was always going to be tight," said the Oxfordshire based team's Australian technical director, Sam Michael.

"So instead of rushing the car out, we would rather wait to do it at the following test in Valencia," he explained.

The team's 2007 car, however, will in Jerez feature the 2008-spec gearbox, to also be used by Toyota, which this season must for the first time last four races.

"For us that is no problem," Michael insisted. "We had already built the 2007 transmission according to the regulations for 2008."