The hottest rumour at the Suzuka circuit on Saturday is that McLaren is contemplating splitting completely with Mercedes at the end of the season.
Germany's Auto Motor und Sport reports that the Woking based team's plan, masterminded by chairman and former team boss Ron Dennis, is to buy BMW's formula one engine division from the withdrawing German carmaker in order to go it alone as an independent chassis and engine constructor.
The move would clear the path for Mercedes to completely concentrate on its intensifying partnership with Brawn, with Dennis thought not keen on the prospect of taking a back seat to Mercedes' new favourite.
McLaren has an engine supply contract with equity partner Mercedes for two more seasons, but Dennis is believed to be confident that - as with his new MP4-12C road car project - the outfit can manage without the Stuttgart based manufacturer.
Auto Motor und Sport said BMW would be interested in selling its F1 engine programme for the right price, and that Dennis may already have made enquiries with the marque's Munich headquarters.
Meanwhile, Robert Kubica on Saturday appeared to express concerns about moving to the Renault or Toyota teams in 2010.
During Friday's FIA press conference, both outfits confirmed their interest in the 24-year-old Pole, who is reluctant to stay at Sauber for next year in the wake of BMW's withdrawal as owner.
Toyota's commitment to F1 is the subject of intense speculation, and the same could also be said of Renault, particularly in the wake of the harmful 'crash-gate' scandal.
"The future of the team (for 2010) is a big factor and big influence on my decision," Kubica told reporters at Suzuka.
"I would not like to be in the same situation I'm in with BMW-Sauber -- that in the middle of the season the company is announcing it's retiring from formula one.
"I do not want to be in this position (again)," Kubica added.
Toyota team president John Howett admitted in Japan that he is chasing Kubica's services for 2010 despite not yet knowing the size of the 2010 budget that must be approved by the carmaker's executive committee next month.
But the Briton said it is still possible to be negotiating over high salaries with top drivers like Kubica.
"The budget is going to be roughly the size it is currently, and you can reduce other areas. If you buy a cheaper driver, you can deploy that in other areas. I think (it's) a very simple equation for us," he explained.