GREATER NOIDA, India - McLaren can deny Red Bull's Formula 1 leader Sebastian Vettel a fourth straight win, Jenson Button said ahead of the 2012 Indian GP Prix."I think Red Bull has upgraded its car so is doing a very good job and, when the car works well, Sebastian gets the best out of it but we don't come here thinking that it's going to be Red Bull all the way. We think we can challenge them here.”The pendulum of form has swung from one team to the another in this unpredictable of season but Vettel has won the previous three races while Red Bull has locked out the front row in the last two.Red Bull is leading Constructors standings by 77 points with four races to go and is 83 points ahead of McLaren which is third, behind Ferrari.Button added: "Yeah, the previous two races have been good for them, but in a way Sebastian was lucky with his first in Singapore with Lewis pulling out. I think there's every opportunity to challenge them for race wins."After a mid-season slump, McLaren returned to form with an upgraded car. The team took a hat trick of victories from Hungary to Italy but reliability woes hurt the title challenge.Button's team mate Lewis Hamilton, his title hopes effectively over, disagreed with Button's optimism: "I think on a dry weekend they're way ahead as they were at the previous race. It seems to have worked pretty well; who knows how many more improvements they'll come up with." Stay with Wheels24 for the 2012 Indian F1 GP weekend.