There's been a fair amount written in these pages about McLaren's stalling preseason test times, and as final preparations continue in Barcelona, the outfit that powered Hamilton to the championship last season is again well off the pace.
As far as McLaren were concerned, there were two eye-catching aspects of the Barcelona outings—they were consistently a second or two off the pace, and they finished up with gaudy, fluorescent green paint spattered on the top, side and floor of the car.
Using paint to show how air is flowing over an F1 car is nothing new, and fairly standard practice for F1 teams, but for McLaren to be doing it so close to the start of the season, and in public is unusual. And it gives us a couple of clues as to what problems they might be trying to overcome.
The fluorescent paint trick allows you to visually trace airflow over the entire length of the car. The aim is to get a nice, smooth, uninterrupted stream of air.
If there are traces of the paint pooling or building up anywhere then it shows a break in this smooth flow of air. Conversely it also identifies points where the airflow is leaving the surface of the car, both of which indicate an aero problem.
So, the first thing that can be inferred from McLaren indulging in a bit of high-speed Spanish redecoration is that they are having problems with the airflow over the top or bottom of the MP4-24.
A situation that would be consistent with the fact that they are still switching between the '08 and '09 rear wings.
Secondly, and this is the interesting bit for me, McLaren aren't a team that readily admits to too many problems or weaknesses (remember how strongly they denied a rift between Hamilton and Alonso even when every single F1 fan in the world could see what was happening), so for them to so clearly show in public that they are battling aero issues is unusual.
Out in the open!
Normally this kind of testing is done on closed circuits, in the wind tunnel or by computer simulation (not least because global marketing managers don't take too kindly to paying top whack for sponsorship space, then seeing their logos get sneezed on at 200mph by a fluorescent green nose cone).
The fact that McLaren feel the need to carry out this kind of testing in public, at race circuits, suggests that an inconsistency between wind tunnel figures and on-track performance is forcing them to.
In reality testing is testing, nothing more. Just as I wouldn't expect Button to win in Australia despite his showing on Thursday, I also don't expect McLaren to be as far back as their times this week suggest. Let's not forget that just a month ago Hamilton was topping the time sheets in Jerez.
One thing is for sure, though—the paint job shows there are still some touch-ups to complete before McLaren are ready for the off.