Vettel on Sunday became the youngest ever driver to rack up four world titles, beating Michael Schumacher's previous record for the milestone by six years with victory in the Indian Grand Prix.
With 36 career wins to his name Vettel stands fourth on the all-time list, and with so much time on his side Formula One's most prized records are conceivably there for the taking further down the line.
Schumacher's tallies of seven world titles and 91 grand prix wins represent formidable targets, but even they could come under threat from a driver who has come to dominate the sport just six years on from making his debut as a fresh-faced 19-year-old.
"Sebastian is not going to get worse, that's for sure," Newey said after seeing Vettel dominate in India.
"He's going to continue to develop, although it's difficult to see how he can develop relative to this season, but no doubt he will.
"As we can continue to build competitive cars then hopefully Sebastian can continue to win more championships with us."
Vettel's win on Sunday was his sixth in succession and 10th overall this season - a display of consistency and efficiency typical of the very greatest talents Formula One has produced.
Newey-designed cars have won countless titles down the years and been driven by the likes of Nigel Mansell, Alain Prost, Ayrton Senna and Mika Hakkinen, and Newey believes Vettel has earned his place in the very top bracket.
"A lot of people have asked me to compare the drivers I have been lucky enough to work with and it is wholly unfair for me to compare them," Newey said.
"But the one thing they do share is that ability to drive and process at the same time. They also have an incredible recall after they get out of the car.
"I think that means that they can drive while considering and planning what they are going to do next in the race. Then, they can get out of the car afterwards and continue to learn and analyse what happened in the race.
"You see it with Sebastian all the time. You have that impression that each time he gets in the car, he gets in with a bit more knowledge than he got out of it last time."
So good is the German at absorbing information and learning from past errors, Newey feels he is now approaching a point where he can be regarded a perfect racing driver.
"His driving has gone from very talented but slightly raw at times, let's say in 2009, to incredibly well-rounded now," he said.
"In 2009 and 2010 you could occasionally criticise him for making slightly ill-judged moves and having accidents, and you could criticise him possibly for not being able to overtake, as a lot of people felt that if he didn't start from pole and control the race from there, then he was not so good.
"But I think you really cannot make those criticisms any more. It is difficult to see a chink in his armour."