Formula One rivals Nick Heidfeld and Antonio Pizzonia face a nervous wait to discover which of them will drive for Williams this season after completing a final head-to-head test in Spain on Wednesday.
The BMW-powered team launches its new car in Valencia on Monday and intends to announce its complete driver line-up at the same time.
Either Brazilian Pizzonia or German Heidfeld will partner Australian Mark Webber, the team's only confirmed driver to date.
Heidfeld, who drove for Jordan last year, ended the afternoon with the quickest lap at the Spanish circuit but conditions were windy and difficult.
Heidfeld lapped in a best time of one minute 10.079 seconds, Pizzonia in 1:10.364.
"I am quite happy with what I have done for the team," the German told the Autosport website. "In fact, I am happy with all the tests I have done since Jerez last year.
"I did all I could and now it is just a question of waiting."
Pizzonia was the favourite for the job until BMW suggested the team test Heidfeld, who had impressed with struggling Jordan and Sauber before that.
{{/usCountry}}Pizzonia was the favourite for the job until BMW suggested the team test Heidfeld, who had impressed with struggling Jordan and Sauber before that.
{{/usCountry}}The last time the team had a similar shoot-out, in Barcelona between Briton Jenson Button and Brazilian Bruno Junquiera in January 2000, the two drivers were not told of the team's decision until minutes before the car was unveiled.
Button was given the nod and within months had become Formula One's youngest points scorer.
Pizzonia will continue on Thursday with Britain's Andy Priaulx also getting a day behind the wheel as a reward for winning last year's European Touring Car Championship with BMW.