As the forklift trucks packed up the motorhomes and emptied the garages at Interlagos in Brazil, it did not take very long for the inevitable question to be asked - just how good a driver is Sebastian Vettel?

Sunday's race confirmed Vettel as just the ninth driver in the sport's 62-year history to win three world titles, joining greats Juan Manuel Fangio and Michael Schumacher as the only racers to triumph in three consecutive seasons.

However, what is telling -- given Vettel is still only 25 -- was the somewhat circumspect response from three world champions and former McLaren race-winner John Watson when asked to assess the Red Bull driver's talents and his place in history.

"It doesn't really change how many races you have already won, getting close to the championship is a big pressure," said Schumacher, the man Vettel describes as his childhood hero.

"Even if he appears to have a car that makes it possible for him, nevertheless he has to do it. He's going for it 200% and it's a very tough job.

"He managed to pull it out and that is the extra effort that comes from him and to do this so consistently is very special."

Rearguard action

This season Vettel had to hold his nerve much more than during his previous championship campaigns.

In 2010, he had nothing to lose as he hunted down Alonso, who had a 15-point advantage, going into Abu Dhabi's finale.

The following year he wrapped up a dominant season with four races to spare and finished 122 points clear of his nearest rival Jenson Button.

This season, Vettel overcame a topsy-turvy start in which there were seven different winners in as many races.

Twice his race unravelled with reliability issues and twice -- in Abu Dhabi and Brazil -- he had to hustle through the field from the back of the grid.

The German only took the championship lead with four races to go and then had to fight a fierce rearguard action against Alonso.

"The interesting part is that this championship has been so hard-fought and it didn't really come together until the last races," said 1978 champion Mario Andretti.

"This season has been one of the best in memory. Vettel is one of the rare talents that doesn't come along very often."

Design genius

Talking of rare talents, the 2012 season demonstrated that if you want to get ahead in F1 make sure you have a good engineer in your team.

No wonder Alonso pointedly half-joked that he was not only fighting Vettel -- he was also fighting Red Bull car design guru Adrian Newey.

When asked if he agreed with Alonso, Newey's face broke into a slow, broad smile before he responded: "No. What can I say?"

Crucially when Red Bull lost some ground at the start of 2012 because of a ban on exhaust-blown diffusers, Newey found a way to recover the car's performance and get Vettel to the front of the pack.

There is no doubt that over the last three years Vettel has had the benefit of a supreme machine capable of squeezing out consistent pace and cornering speeds on a variety of circuits.

"Everyone that [wins the championship] hasn't done it alone," added Andretti, who dominated his championship-winning season thanks to the legendary Lotus 79 ground effect car.

"You can have the best driver in the world but you need the car. When Schumacher and Fangio were winning they had superior equipment as well. Vettel is making the most of the best design in F1. That's what it takes."

Peerless car

Three-time champion Niki Lauda certainly believes that when you're racing in a field thick with five other world champions having the best car is a useful weapon.