Rosberg: Williams close to car solution

Although Williams started the year strongly, with Rosberg taking a podium finish in the season-opening Australian Grand Prix, the team have endured a more difficult middle part to the season where they have struggled to score points.

Work at the factory, however, has unlocked some explanation for their issues and new parts tried out in Hungary last weekend suggest that they are now heading in the right direction to get on top of their issues.

"We've got the bottom of one of the problems, yes," said Rosberg. "We have an explanation for it, especially when you consider that in the winter we were level with Red Bull and Toyota, and it's just gone down.

"But we know where one of the main areas is and actually I have learned something in Hungary, which was just a small step in another direction, to give us an idea if it's the right thing. I ran it in qualifying and it's quite positive."

Although optimistic about Williams' chances of recovering from their mid-season troubles, Rosberg still thinks it will take a few weeks for further progress to be made. Matters are also not helped by the summer testing ban.

"The problem is in F1 it takes time," said the German. "You have to design it, then you have to produce it, test it, put it on the car. We won't see it in the immediate future - it's going to take a few weeks."