This weekend's Spanish Grand Prix marks the 'real' start to the F1 season with most teams preparing a raft of new developments - but what is in the pipeline and who is likely to make the biggest jump?
The opening four flyaway races left teams little room for manoeuvre in terms of major new parts (especially with the added challenge of the Icelandic volcano) but plenty of time for design office thinking back at base.
Many have stored up several new design improvements ready for release as a big step package this weekend, so there should be some intriguing additions that could alter the order.
So far, McLaren are out in front with two wins from four, while Ferrari lie second thanks to their season-opening 1-2 finish. But the real pacesetters, Red Bull, are in third having failed (on most occasions) to make the most out of what is clearly the fastest car on the grid while Mercedes have fallen short in the opening rounds.
So how are things about to change?
McLaren highlighted the benefits of this clever system at the start of the year and now many rivals are developing designs of their own to take advantage of the idea.
While the top-speed advantages of this have been widely focused on, its real gain is that it allows teams to run extra downforce at lower and mid-range speeds and not suffer for it on the straights at higher speeds (because they can actively reduce the wing's downforce levels and therefore reduce its drag).
McLaren have said they already achieve the maximum performance they can obtain from this device, so now their advantage can only diminish. That said, the complex solution is not easy to perfect - as shown by Sauber's efforts - so that may not be so clear-cut.
Of the top teams, Ferrari and Mercedes both tried out designs in China with Ferrari's system only a passive mock-up, designed to test the implications of the altered engine cover rather than the actual workings of the design itself.
Mercedes used a different solution to McLaren's, with their device seemingly contained entirely in the rear wing with two slots that sit around the air separation point on the leading edge of the wing used to determine when the device functions.
Ferrari's design appears to be more conventional and the fact that they have used one of their four available aerodynamics test days to further analyse it's benefits between China and Spain should put their design a little ahead of the other teams developments.
Red Bull have said they are not rushing their version through - but don't be surprised to see them trying something out in Spain as well.
Mercedes has admitted they got things wrong in terms of weight distribution this year and they will bring in a new suspension (which changes the car's wheelbase) to correct that in Spain.
That will fundamentally alter how the car handles - and so if they get it right it could bring them into the mix at the front of the field.
In contrast, at the back of the grid Virgin will bring in one car with an expanded fuel tank following their under-sizing mistake. That too is likely to alter the car's weight distribution and could actually negatively change their fortunes given their initially strong (if fragile) performances compared to the back-of-the-grid rivals.
The fact they will be running one new car and one original will also prove an unwanted challenge.
Everyone will have new parts to add on but some will have more than others. Because of their new wheelbase change, Mercedes have potentially the biggest opportunity to gain or lose, with a raft of new developments necessary to cope with the change in aerodynamic balance and the altered position of the front and rear wheels. It could almost be to the levels of a 'b-car'.
McLaren have admitted they are traditionally poor in high-speed corners, something that is important in Barcelona, but claim this has improved this year. Team boss Martin Whitmarsh, however, admitted it "isn't enough to suggest a complete reversal of our recent fortunes in Spain" but they will bring in new front and rear wings that they hope will add significant benefit in this particular area.
Alonso, meanwhile, believes Ferrari have got on top of the engine reliability issues that have hampered them so far - and he is also confident that they have a number of new parts for Barcelona that good enough to make him claim they will catch Red Bull in qualifying pace.
And at the back of the grid, Lotus boss Mike Gascoyne has brazenly talked about a "more than one second" jump in performance from a raft of new parts coming out of the team's factory - claiming the early design freeze they implemented to give them time to prepare for the season means they have more to gain on their rivals.
All teams with mirrors mounted away from the chassis must now move them inboard, and that will affect the clean flow to the rear wing.
Ferrari and Red Bull are likely to be most affected, as they run their mirrors extremely wide on upright turning vanes in front of the sidepods, but it is not expected to have a particularly significant effect on performance so should not be a major issue for any team.
So there is all to play for as the European season kicks off.
Renault, meanwhile, have been knocking on the door of the top four, but they have done so by bringing in a series of strong developments during the flyaway races. They have another new front wing, and a couple of other parts, but are unlikely to have the level of steps their front-running rivals have stored up.
"It's not the biggest update we've had this year," admitted Alan Permane. "But I don't think the balance will shift dramatically."
Others beg to differ.
But with weather predictions suggesting rain could yet again cause confusion during the racing weekend, strategy plays could be as important as development parts and it could be a few races yet before real dry running allows a race to be won on ultimate performance...