The relentless development race has continued unabated this weekend as Red Bull bolts on updates at the eleventh hour. While most teams are already fully focussing on 2013, Red Bull continues its development programme as it guides Sebastian Vettel towards a third consecutive drivers' crown.

To that extent, a new rear wing arrived in Sao Paulo on Friday morning, along with some new bodywork.

Red Bull has endured a nervous week after Mark Webber was forced out of the United States Grand Prix with an alternator failure. "The alternator is a concern," admitted team boss Christian Horner during the week.

"It is something Renault need to get on top of this week," he continued. "They have run different solutions on different cars and hopefully they have enough data now to make sure we have a reliable version."

The alternator first proved a problem at the European Grand Prix when both Sebastian Vettel and Lotus' Romain Grosjean were forced out. The issue reappeared in Italy, while a new alternator was available to Renault powered teams last weekend. Red Bull opted to stay with the revised alternator it had used since Italy without problem.

Red Bull spent the opening day working on setup for the race, while taking the opportunity to test some ideas aimed at next season. "We got through plenty of stuff and also did a bit of '13 work," revealed Webber. "It's the last test before next year, so we made the most of the beautiful sunny day in Brazil, before we go to colder Jerez in February."

Vettel and Webber were second and third respectively in both Friday's practice sessions, just off the pace of Lewis Hamilton's McLaren. Fernando Alonso, Vettel's championship rival, was fifth in both sessions, about two tenths off the pace of the points leader.