Formula 1's pre-season testing moved up a notch of intensity on Saturday when Red Bull Racing unveiled its latest updates at Barcelona. McLaren is also set to bolt on a new upgrade later today or tomorrow.
With just two days of testing left before the season-opening Australian Grand Prix, rival teams are now making the final preparations to their cars with their latest development parts.
Most of the focus on Saturday morning at Barcelona was at Red Bull, with the team having fitted its latest aerodynamic package to a chassis that it has brought to the track for the last two days of running.
Mark Webber gave the new car - which features a number of updates including a heavily revised exhaust layout (similar to Sauber's) and a new front wing - its first lap on Saturday morning with world champion Sebastian Vettel admitting that the next two days were crucial.
"We have some new bits for the next two days and then we'll know a little bit more," he had said on Friday. "Everyone is a bit in the same situation. Usually the last couple of days of testing are quite important because you bring some new bits and the car is closer to what you will race at the first race, so we will see if that comes true.
"Hopefully we can make another small step forward and then we should be okay."
Webber completed a single installation lap of the car on Saturday morning, before the RB8 was returned to the pits for post-run checks prior to further tests.
Red Bull showed how keen it was to keep its design under wraps from the opposition as the car was heavily shrouded by covers as it returned to the pits, and mechanics swarmed over the car to keep photographers at bay.
AUTOSPORT's technical correspondent Gary Anderson believes the updated Red Bull Racing RB8 is a big philosophical change from the version tested already - especially with the revised exhaust layout.
"It is March 2 today and that is a whole new package from Red Bull, which is impressive this early in the season," he said. "They had a good advantage last year with the exhaust pipes - and they know how that area of the car operates so they are continuing to push forward in that area."
Anderson believes that the location of the exhausts is aimed at getting the gases attached to the airflow around the rear Coke-bottle area of the car.
"The exhaust pipes are further forward on the outer part of the sidepod," he explained. "They are not blowing anywhere in particular, but there appears to be some idea of getting the exhaust gases attached to the bodywork and being channelled somewhere they don't want to go.
"That is why they have detailed that Coke bottle area much more - plus there appears to be a large duct on the underfloor, feeding the flow between the double-skinned floor, to the diffuser."
The revised front wing on the RB8 features a straighter mid-section, which differs from the curved design the team has run up until now.
See all the latest images, including those of the updated RB8, in our testing gallery.