Well good old Jacques is a controversial guy (who I really respect a lot and even sometimes agree with some of his view points...but sometimes he just has it completely wrong) and Piquet Jr lost all respect long ago.
You can't get good results without a good car but a good car doesn't drive itself. Personally I always think people are just getting into a maze of confusion when they try to pick apart and decide whether results are because of the car or the driver.
Its the overall package that gets the results.
Funny that at the start of the year when Raikkonen was struggling with power steering people blamed him for not being adaptable and too demanding. Now he's delivering people are saying its all the car. To me that says that Raikkonen is driving just fine and the overall package has evolved both from car and driver. Kimi has blown the cobwebs off and got the team and the car understanding what he wants. And the car has obviously found more pace through the season, especially as we go to hotter races.
I also think a good indicator of when you know your drivers are extracting all the pace from the car is when both drivers are very close in laptimes. I mean possibly there is an argument that 2 slow drivers could run similar laptimes but personally I think its pretty unlikely both Raikkonen and Grosjean are slow.
I can't think of one example where a team had 2 drivers who clearly were both slow. Usually one is much faster than the other. I can think of quite a few that were even. Some of them are on the grid today and funnily enough 2 such teams are mentioned here (Sauber and Lotus).
People basing their opinion on Grosjean being slow from 2009 always seem to forget that actually Romain was pretty close to Alonso in qualifying near the end of the year. Much closer than the great Piquet Jr. Sure he wasn't consistent and made a lot of mistakes but he was a rookie. Mr Piquet made lots of mistakes, didn't show much pace and didn't show any sign of improvement in his second season. Grosjean has shown a huge sign of improvement.
Thats not just the car.