For Australia we’ve seen a number of updates. RedBull are using new bodywork around the exhaust and a new rear floor with added vanes to aid the Coanda effect in guiding the exhaust gasses around and under the side of the diffuser and away from the tyres. The floor had a cutout in it very slightly ahead and alongside the rear tyres, into which the exhaust gasses would flow into the side channels of the diffuser. The bodywork around the exhaust is a little more angular in profile as you can see from the image at the link below. The exhaust gasses expand outwards by a larger amount than you’d expect, but the general flow direction seems to stay the same as is visible from the scorch marks.
McLaren are running a new rear wing (with the Lucozade sponsors logo on it)which has the centre section of the upper flap (in between the slot gap seperators) being a few mm lower than the outer sections. This very slightly reduces the downforce, however it also slightly reduces drag when DRS is both open AND closed.
Ferrari have brought a small and virtually unnoticeable change to their rear wing endplate. It now features 3 horizontal vanes. I don’t know what these do, but I would hazard a guess that they produce a small vortex, which enhances the expansion of airflow from under the rear wing main plane, which reduces pressure and increases pressure differential. The uppermost one is shaped to follow the exact same arc that the upper element does when the DRS is activated.
They also have altered the layout of the exhaust yet again, as they try to find the solution that works the best for their car.
Lotus-Renault have a small, but visible and most probably overlooked aero update to their sidepods. The foremost upper section now has a vertical vane protruding above it at almost half way between the side of the cockpit and the turning vanes on the outer edges of the sidepods. I’d imagine this is to guide airflow over the top of the sidepods to increase airflow to one side of the exhausts. It also would produce a vortex over the top of the sidepods, similar to that of which aircraft use.
Torro Rosso are running a new rear wing. Their main plane now curves upwards at the outer edges giving a deeper central section. With me being only an amateur, my guess as to why this is used is because it gives a slightly larger surface area on the underside of the wing compared to the top of the wing. This therefore means that the airflow underneath has to spread out more, giving a reduction in air pressure, and a greater pressure differentiation between the two surfaces. This therefore produces more downforce with not much more drag.
Caterham have finally brought their new front wing. The uppermost, rearmost flaps are virtually the same, but a new endplate and a new main plain and 2nd flap have been installed. Also includes new cascade elements. This follows the general trend where the main plane is split into two sections after the FIA standardized 50cm section in the middle of the wing.
HRT seem to also have brought updates to Melbourne. If you can call them updates. At their ‘filming day’ in Barcelona, they were running a car without DRS, barge boards or cascade elements on the front wing. They seem to be using EXACTLY the same front wing that they were using for virtually all of 2011, bringing back the cascades that they introduced a few races in. Let’s just hope that they are better made. They did keep coming off last year don’t forget!