BMW introduced a major development step on its car at Valencia, and the results were immediately there. The single point of Robert Kubica may not seem much, but at Bahrain there were still miles and miles away in the back of the field, while now Kubica could fight Webber, a race winner this year.
BMW Sauber decided gambled with KERS and failed badly, hence they decided to ditch it alltogether. The result now is a lighter chassis and much more sculpted sidepods. The team redesigned the whole sidepod package, including the position of the radiators inside them. Previously there was room for the KERS system, located left and right of the car's fuel tank. With the radiators now located closer to the centre of the car, the aerodynamicists had more room to play and the body's roll will have decreased due to the tighter packaging. Everybody happy.