During qualifying, until just before the race, teams must adhere to Parc ferme conditions, and once qualifying is over, the cars must be left in the Parc ferme area. A common misconception is that once the cars are in Parc ferme, they are not allowed to be touched, but in fact, any changes to the cars are monitored and strictly routine.
The cars must be in the secure area by half past six on a Saturday night, and are released at half past eight on the Sunday morning. Until then, the FIA carry out stringent checks to make sure that the cars are legal.
The Technical Delegate produces a document detailing what goes on during this Parc ferme period, and it is released to make sure that no one has bent the rules. The document is available on the official FIA website as a PDF, so even fans can read it, if they so desire. I can tell you itís interesting to look at once, to see the types of changes that are and arenít allowed, but itís not something I would read every race.
Procedures that are allowed under these conditions include very minor repairs, such as bleeding the brakes, checking and replacing gear discs, and adding or taking off small amounts of front or rear wing. The cars can be topped up with fuel Ė in the case of the top ten, they can only refuel to the level they started Q3 with. Tyres can also be changed. In fact, the FIA can give the teams special permission to change the tyres, if the weather requires it. If qualifying is dry and the race will be wet, then wet tyres are allowed to be put on.
If a team makes any major changes to their car, then they must start the driver from the pit lane, which is effectively the back of the grid. If the car needs an engine or gearbox change, then they incur the standard penalty Ė ten places for an engine, and five for the gearbox. These penalties can all severely impact a drivers chances at getting points and podium places, and it is therefore in a teamís interest to make sure the cars are completely set up for the race by the time qualifying begins.