Pastor Maldonado was seen running in the Williams FW35 featuring the stepped nose and front wing of last year's FW34. Williams have lost the direction for its aerodynamic development, and as updates do not bring the expected progress, the team is now checking the efficiency of the car with better known elements, such as the 2012 nose cone and a front wing used late in the 2012 season.

Mike Coughlan, the team's technical director said "We were running different parts across the two cars this morning to try to improve our overall performance. We were happy with what we saw with Pastor’s car, but we made some changes this afternoon which didn’t work as we wanted, so we will be comparing the data from this morning to bring back the performance"

Indeed, the car appeared to work well with the older nose, which may point to a problem of airflow interaction between the front end of the car and the leading edge of the floor. Despite the progress, AmuS have learned that the team will be unable to use the 2012 spec elements as they might fail the beefed up front wing strength test.

Ahead of the season, there were already strange things going on at Williams. During winter testing the FW35 sometimes appeared with a lower nose, and other times with a very high nose, similar to the FerrariF138. The team was undecided even then, but denied there was a struggle going on. Instead they mentioned "ongoing evaluations" as the reason. Since then, the team also reverted from their ramp exhausts to a version similar to the 2012 layout.

Toro Rosso have perhaps introduced the biggest update package of all teams at Barcelona, with the STR8 now being fitted with a new ramp style exhaust. The team have however not exactly copied any of the existing designs but instead opted to go their very own way and come up with a very special ramp.

Previously the team had an exhaust more similar to that of McLaren, but the new version should help draw the exhaust gases down better, or at least in a more controlled way. Just like with Lotus and Red Bull, the sidepod included an undercut that helps channel air underneath the sidepod onto the central part of the diffuser. The particular thing here is that Toro Rosso's channel is entirely open while all other versions feature a closed channel. As this is of course the initial version on the STR8, more development in this area is likely to appear in future races.

Feedback from the drivers is already positive, with both saying the car is much more stable and easier to setup.

McLaren have pinpointed their problems of 2013 to a problematic correlation of wind tunnel data and struggling to get a persistent airflow around the Pirelli tyres, which are now flexing differently than last year. Jonathan Neale even likened their problems to those at Ferrari last year, saying the Scuderia people will surely know how it feel to be in the position McLaren is currently in.

As a first step to resolve some car problems, the team introduced a modified sidepod panel that now features a bridge to connect to the shoulder of the sidepod, similar to what can be seen on the Red Bull RB9 and by now on various cars. Although not perfectly visible on the image, the bridge is actually quite thin, with a much shorter chord than the vertical panel actually is.

In the same move, the vortex generators on top of the sidepod are back, reverting from the horizontal winglet that was copied from Lotus earlier this season.

Caterham have introduced the second part of their major upgrade package for the CT03 which should help the team get ahead of Marussia again. Part of the update package was moved forward and introduced on Charles Pic's car in Bahrain, including the bulge under the nose, revised rear wing endplates and the new sidepod panels.

This time around, the focus was mainly on the front end, with a raft of updates aimed to help increase front downforce. The most obvious change of course is the vanity panel on the upper side of the nose which now hides the ugly step. Although this is likely to give only a marginal aerodynamic improvement, it's still a big improvement to the eye.

More importantly for the car's efficiency is the new front wing that finally ditches the unconventionally big stepped element, replacing it for a wider, shallower 2-element winglet similar to what other teams feature on their front wings. The main panels have also been revised, with notable changes on the inner edges and a smaller slot gap between the wing's base and the first flap.

Furthermore, the brake ducts have been revised to add a vertical fence that extends further forward and new turning vanes appeared under the nose, now more similar to the designs of Red Bull Racing and Ferrari.

Despite only having a 7 day gap since the Chinese GP, Ferrari have brought another update to their F138. The team fitted new sidepod panels on both their cars during the entire weekend, increasing the volume of the sidepod around the UPS logo. The difference is clearly visible when you focus on the joint of the foremost panel - with the Shell logo - that was unchanged and the new panel with UPS on it.

The previous design had fairly visible downward ducts, still somewhat similar to their "Acer duct" naming of 2012, although they would now have to be called "UPS ducts". Now, the underside of those ducts has been beefed up. While it is hard to say what exactly the team is aiming for, it is possible that Ferrari wants more air to flow alongside the UPS logo rather than pushing it down towards the floor.

Also visible in the picture are the new shark gills close to the car's floor. These are added to increase cooling performance but are likely to disappear again at events with lower ambient temperatures.

Caterham F1 have brought the first updates to their CT03 since the beginning of the season. The team urged a few updates as soon as it appeared that there were considerably issues with the car that would make it unable to put up a fight to any other team. The updates seem to have had an immediate effect, with Charles Pic saying after free practice that the team were to adjust the car set-up as the updates immediately brought in understeer thanks to increased downforce at the rear of the car. A more comprehensive number of updates will be added at the Spanish GP in 3 weeks time.

So far, the updates were only tried on Charles Pic's car, including a new bulkier nose that copies an idea pioneered by Lotus last year to help clean airflow underneath the high nose. Sauber and Force India are teams that have followed that trend before, with Red Bull trying it on last year's car as well.

Perhaps more importantly is the new Red Bull style panel aside of the sidepod. This greatly helps control how air ends up at the back of the car.

Red Bull introduced a new beam wing on its RB9 this weekend at Bahrain. The new version will generate a little bit less downforce than the more conventional one used during the first 3 races of the season. Although a smaller beam wing it itself is nothing special, the roundings on the trailing edge of the wing are interesting indeed. The element is aimed at generating more downforce close to the centreline of the car while the reduced frontal area will cause less drag and downforce closer to the rear wing endplates.

Also new on the RB9 is the different cut-out on the central hot air outlet, aimed at keeping the car's internals at acceptable temperatures in the heat of Bahrain.

Red Bull Racing have copied Williams' hollow front wheel axle and wheelnut to allow air to pass through. Identical to the Williams version that was used since winter testing, the wheel nut is empty in the middle, which allows air caught by the brake ducts to flow out in an attempt to control the front wheel's wake. The latter is an important factor for rear downforce and also explains why teams are not using a similar system on the rear wheels, where it is more beneficial to have smaller brake ducts.

The system was only seen in the Friday practice sessions on Sebastian Vettel's #1 car.

Already since the Chinese GP of last week, Mercedes are running a slightly different front wing which includes a tiny lip on top of the stacked element support.

Also marked in the image are some interesting details which show how much attention Mercedes have put into this new front wing after basically struggling with that part of the car for several years. The support for the stacked element for instance is not as simple at it may initially appear as it is clearly shaped differently long its height.

One other thing that is remarkable is the shape of the flap support, including the front wing adjuster. At most teams these are two separate element or a more solid item, but Mercedes have clearly put effort into making this item as small as possible to create the least possible effect on the airflow.

McLaren has introduced a modified sidepod bodywork design that features a bump on top of the sidepod. In fact it looks like the fat lady sat atop of the sidepod, creating this new version. The idea is to draw a little bit more air down onto the exhaust more rapidly, helping the curving down of the exhaust gases aft of the exhaust channel. The difference of course is clear because of McLaren opting to paint less of the car's bodywork in silver.

The design is not new at all and follows a trend set by Mercedes as their F1W04 features a similar dent in the middle of the sidepod, creating a mild U-shape in the upper surface. Lotus have recently done a similar design by applying it on their ramp style sidepods.

As an aside, also note that McLaren ran without gills underneath the upper frontal wishbone, hinting at either modified internal cooling channels or simply because the Chinese GP weather posed less of a challenge than the burning heat of Malaysia.