No I don't think that's right. Mercedes has said McLaren won't let them, Ferrari would require approval from the FIA and other teams, the Toyota is rubbish, the Cosworth unproven and Renault are playing hard to get. Of course you're right that they are not 'forced' to use Cosworth engines but they clearly will have trouble getting the best powerplants so I don't see how it diminishes my point in any way.

Williams has spent the money and the rules allow KERS. That's an edge they've already paid for and that they are likely to need next year.

Based on what you have written here, you assertion that William's is a Hobson's Choice is tacitly untrue as they may choose - at least - between the Toyota and the Cosworth unit.

I really think that whenever we get to see the engine speczation stuff and that BMW, Renault and Toyota will be allowed to catch up with Mercedes and Ferrari...

Then what shall we see?

Both of them will put KERS on their cars for 2010, which is even bigger advantage for 2010 with the increased weight os the cars, with all the fuel onboard at the start of the races and with the narrower front tires.

If I am not mistaken, it's not that Renault will be allowed to catch up with Mercedes, it's more like Mercedes will have to detune their engine to Renault's level.

Here is another brilliant idea conceived by FIA, and fully endorsed by Mr. Mosley: Screw the success!

Williams have every right to use KERS if it is still in the rules. End of.

IIRC Williams were never excluded but rather had their membership temporarily suspended. And I am not sure whose intiative it was restoring their full membership.
But it is strange that a team who always moan about being a small one and not having enough money, who happily accepted the budged cap and the idea of a two tier championship, to announce they're planning to use KERS while the bigger teams have decided not to for the sake of cost cutting.

Did McLaren develop theirs or did they buy it in 'kit' form and assemble it?

Neither, Mercedes HPE got Zytek to design it.
http://www.zytekgroup.co.uk/Default.aspx?tid=405

Thank you.

I read in another place that Williams (Head?) has said they might agree with the third car idea.

"If somebody was running Alonso, Kimi Raikkonen and Michael Schumacher - for instance - I'm not sure that would be ideal."

Neither, Mercedes HPE got Zytek to design it.
http://www.zytekgroup.co.uk/Default.aspx?tid=405

Not entirely according to that article. Zytek did the motor and the power electronics (actual controls has to be the standard ECU, doesn't it?) but somebody else did batteries and other unspecified parts. That is a 'kit' of some sort

Does anyone remember an article with pictures of the McLaren KERS parts? It had all the parts laid out for comparison, but I can't find it now.

Not entirely according to that article. Zytek did the motor and the power electronics (actual controls has to be the standard ECU, doesn't it?) but somebody else did batteries and other unspecified parts. That is a 'kit' of some sort

Does anyone remember an article with pictures of the McLaren KERS parts? It had all the parts laid out for comparison, but I can't find it now.

http://www.youtube.com/watch?v=h4_Nmr2Hmwc this?

Q. (Dan Knutson – National Speed Sport News) A question to all four of you: given that FOTA is all about unity and co-operation, given that some elements in this paddock would like nothing better than to divide and conquer, what do you guys think about Williams going against the grain and running KERS next year?

Sam Michael: One thing to be clear on: Williams have always said that we supported KERS, the concept of it, the ability to help Formula 1 with sustainability and the environment. We haven't stopped the development of KERS and we never did do that, just like the other teams didn't. I think at the moment we are discussing with FOTA the potential for an agreement not to run KERS next year. We are in the middle of that, in terms of days, so it would be wrong for us to come out and say that we are going to race KERS next year. In fact we never said that. In any statements, if you read carefully what we said was... at no point did we say we were going to race KERS, we just said we would continue developing it. I think if you ask most of the people who have KERS, they're doing the same thing. So it's quite different to say that we're going against the grain of FOTA. We are in FOTA, we've only had one meeting in FOTA since we rejoined, so that is in the middle of process at the moment. I think it's wrong to say that Williams are going against the grain of FOTA, especially at this time when we are talking to FOTA about exactly this point.

wasn't williams' idea to place the generator behind the gear box? or did they abandon that idea and place it between the driver and the engine?
Kers headers? I assume that is the bit of the crank shaft that connects to the kers? is it something that is bolted on to the shaft? does it form 1 part with the shaft? Is a engine manufacturer allowed to change this part/ does it fall under the restrictions? is it possible for a team like williams to make a new crankshaft? Is it allowed in the rules?
a lot of questions, sorry.

I think KERS could spice up the racing as long as everyone has it.

In fact, I also tend to think Williams are using KERS as a bargaining chip for somethin else they want.

I managed to obtain information, that Williams agreed not to use KERS next season, as did all FOTA teams.