Just coming back on a few points.
"Could this be a stepping stone for Toyota to pull out of F1? "
Yes. Especially............
"If they continue to flop, and Williams shine with their engines."
"The only problem is that Toyota are giving themselves a rod for their back, coz if Williams win a race before Toyota do, heads will roll...literally."
Don't know about winning but Williams have had a great slow track chassis for two seasons. What they have lacked is grunt from a strong engine. As I see it the BMW and the Cosworth engines have had the bhp there in a very narrow range. I do see the possibility of Toyota ducking out of their massive F1 liability but its also possible that the rod will be on the F1 team's back. All in all I'd say that Toyota management would be quite happy for Williams to do well with their engines. Either Cologne shapes up or they are all out of work and Williams effectively becomes the Toyota works team. It all comes down to WIlliams being allowed to beat the carp out of Toyota whoever is winning races.
"shows how bad it is williams are using the same engines this weekend they used at monaco"
I thought that at first but it may be a good tactic. It is cost effective to run them on as they have only done low mileage and have had the benefit of allowed repairs. That will mean Williams can take new engines to Canada and hopefully not have to ship out new ones again for USA. No one ever accused FW of wasting money.
The other tradition of Williams is that they build cars any idiot can win in. That may no longer be true but the idea that cars are more important than drivers is sound business. If you have the car, drivers will queue up to get in it at whatever salary.
Nico bites yer tyres!