Caterham modified since Melbourne the way rear wing is supported on the car. The new structure involves a single pillar, which splits into two separated elements around the terminal exhaust pipe before both meets the rear crash structure. The old design had instead two thinner pillars starting parallel below the main plane but inclined inwards when dropping down, meeting also the rear crash structure . As a side effect the mini plane above the exhaust terminal pipe had to be redesigned and remounted, adopting now a Williams alike support.
The transition to the single pillar concept may offer not necessary an aerodynamic advantage over the older design, but another more practical one. The wider single pillar provides a larger internal volume and thus being able to house the connections of DRS to the main car body, thus offering a more direct and shorter route, making it more reliable and compact.
Amazingly ToroRosso tested from launch to the very first 2014 race in Australia three in total rear wing specs, very similar in basic structure but different in details. The spec for Melbourne race was similar to the one seen in launch, having two flap fasteners and a curvy upper flap. The team tested during Winter testing one more version with three flap fasteners and reshaped upper flap, an evolution of which having a single pillar briefly equipped on Jean-Eric Vergne car for the Aussie GP free practice sessions.