3 out of the first 4 places on the grid for that race being Newey designs suggests it again wasn't completely down to Vettel. Of course he had to do the rest, but to suggest that the Toro Rosso was not a front-running package for that Grand Prix is missing the entire point.
I think you have a point, but I maintain that the 2008 season is more than enough evidence that Vettel can perform in a car that isn't the best, an accusation consistently lobbed his way. Let's look at the results of the Toro Rosso pairing in the second half of the 2008 season - that is, when the car appeared to take a step forward post-Silverstone.
Hockenheim - Vettel 8th, Bourdais 12th
Budapest - Vettel Ret, Bourdais 18th
Valencia - Vettel 6th, Bourdais 10th
Spa - Vettel 5th, Bourdais 7th
Monza - Vettel 1st, Bourdais 18th
Singapore - Vettel 5th, Bourdais 12th
Fuji - Vettel 6th, Bourdais 10th
Shangai - Vettel 9th, Bourdais 13th
Interlagos - Vettel 4th, Bourdais 14th
From this, I think, we can deduce that the Toro Rosso was rarely more than a midfield car in 2008, and yet Vettel ran consistently in the points, snapping at the heels of the big boys, and, on the one occasion when he was given a front-running car, won the race. What more can be asked of him? Even taking Monza out of the equation, his 2008 for me proves that he can compete in a difficult car.
Not that I believe we should take Monza out of the equation. Let us not forget that he simply motored away from Kovalainen's Mclaren, which started alongside him on the grid and yet finished some twelve seconds in arrears. I do not believe that the Toro Rosso was a better car than the Mclaren, at this or any other race in 2008. Furthermore, after his bad luck at the start Bourdais, himself no mug - he was a serial winner in America, after all - was able to recover only to 18th place. Had that car been the best in the field I would expect Bourdais to at least be in the top 10 in spite of starting from the back.
The following season, Vettel hopped into a Red Bull and secured the team's first victory at his third attempt, leading home experienced and highly-rated teammate Mark Webber.
So, in my opinion, Vettel has more than proved he can perform even without the best car, and as a result must take some credit for delivering four straight titles, even in the best car. Like all great teams, it is the combination of car and driver that is so hard to beat - I don't believe any of Jim Clark's teammates even looking like winning a race during his dominant 1963 season. It doesn't mean that he doesn't have the best car, of course, but it equally proves that it isn't all down to the car - Webber has never been WDC runner-up, as you would expect if the car was as good as the 2004 Ferrari or 1988 Mclaren.