Why did Vettel stay in his car?

Shortly after Saturday's final qualifying session for the Chinese Grand Prix, Red Bull Team Principal Christian Horner was asked why Sebastien Vettel had remained sitting in his car for some minutes after pulling to a stop in parc ferme. "He was just waiting for the FIA to say it's ok to get out," suggested Christian in response.

Now, whilst it's surely just a matter of time before the drivers do need to seek permission to alight from their vehicles, such parental guidance is not a current requirement. Moreover, Sebastien remained sitting in his car as the rest of the top ten pulled up, clambered from their cockpits, and departed elsewhere. So what exactly was he up to?

Red Bull, of course, have encountered serious problems with their KERS system in each race so far this season. Both drivers were without the system in Australia, whilst in Malaysia, Mark Webber noticed a problem with his KERS system as he drove round to parc ferme after final qualifying. Despite replacing the battery pack, Webber was subsequently bereft of KERS in the next day's race, and even Vettel's system began to fail during the final stages. Webber was then deprived of KERS in Saturday's qualifying session for the Chinese Grand Prix, after a problem with the wiring loom.

The KERS system used by Red Bull has been analysed by the superb Craig Scarborough, who points out that both the control system in the right-hand side-pod, and the battery pack in the left-hand sidepod, run at high temperature, and require their own cooling systems. The location of the battery pack in the sidepod, rather than beneath the fuel tank, is unique to Red Bull, and it seems likely that the Red Bull system is overheating. A resolution to the problem will presumably require a re-design of the installation, unavailable until Istanbul at the earliest.

Moreover, it may be that the heat soak after the car completes a series of laps, and comes to a stop in the pit-lane, is a particular problem. Could it be, therefore, that Vettel was sitting in his car, keeping the cooling pumps running until the temperature of the control unit and/or battery pack had reached an acceptable level?