Insufficient rear downforce production was noticeable on Sauber and thus team soon pushed to develop new rear wing designs towards downforce increase .
The initial wing version seen in Jerez had two distinctive V cuts on the trailing edge of the movable upper element where the two flap fasteners exist, while the main flap had a slopping downwards profile close to the endplates to benefit as possible from the clean airstream coming unblocked by the main airbox body. Such main flap design philosophy springs its origin from old Renault team (now renamed Lotus) back in 2006 .
A new version put under test in Bahrain two weeks after which had a wider main flap and three fasteners this time. The upper element was also new because it featured only one V cut in its middle section now. Additionally a mini plane made its appearance above the rear structure.
For Melbourne the Bahraini spec modified further, regaining back the two flap fasteners structure design but loosing the V cut. The mini plane also removed .
PS= The V cut bleeds pressure from the wing decreasing drag with small negative impact on downforce production