Brawn GP Formula One team members push their car into the pit as they prepare for the upcoming Chinese F1 Grand Prix in Shanghai April 16, 2009. Formula One championship leader Jenson Button's title hopes received a significant boost on Wednesday when a Paris appeal court ruled the Briton's controversial Brawn GP car was legal. The International Automobile Federation (FIA)'s court of appeal also cleared Toyota and Williams, whose cars use similar 'double-decker' or 'split-level' rear diffusers and which rivals had claimed broke the spirit of the rules. [Agencies]