Nabbed by a motorsport representative for an interview with the Otago Daily Times during the national championship rounds at Levels Raceway earlier this month, Hartley is obliging but fidgety.
He arrived home in Palmerston North having spent 11 months away, during which he made a promising debut in British Formula Three (F3), and found he has suddenly shot to national recognition status, perhaps courtesy of the New Zealand media exulting in his recent 370km of mistake-free testing in Red Bull's Formula One car at Spain's Jerez Circuit last month.
Coupled with his leap up from British to European Formula Three racing - the breeding pool for future Formula One (F1) drivers - this year, it makes for a noticeable fan factor increase.
Punters approach him for autographs and photos, or nudge each other when he wanders out among the Timaru circuit's pits.
He makes a few benign references to be hounded by the local press and although infinitely polite, he fiddles and twists in his seat.
Growing fame is taking time to settle on his 19-year-old shoulders but for the most part, Hartley takes it all in his rangy stride.
This is the boy, who at 16, was "thrown in the deep end" and crossed the globe to compete with a German team in the Formula Renault 2.0-litre German and Euro-Cup Championships.
He survived a solitary first season living alone in the eastern part of Germany and racing at completely foreign circuits.
Adapting to a tough situation can be hard on the head but preparing to take on the best drivers in the world in the fastest cars on earth generates tenacity.
"When you are racing, it's quite important, your mental state," Hartley explains, adding that what is learnt on the track can be transferred to other facets of life.
His month at home is hardly a holiday as he will keep up the strength-building training necessary to ensure his place in the Red Bull racing junior development squad is never taken for granted.
"If you are not putting the effort in, they are not going to put the effort into you."
Just in case the team bosses want to make sure he is not slacking off, Hartley's watch sends back heart rate data.
His noted commitment and 2008 F3 endeavours led to him being asked to fill in for injured Australian Mark Webber in testing next season's Red Bull Formula One car.
The young Kiwi had secured several victories during his maiden campaign and finished third overall behind team-mates Jaime Alguersuari and Oliver Turvey.
The drive which garnered the most respect last year was his remarkable sprint from 20th to finish third in the F3 Macau Grand Prix in China, where he set a lap record on his 15th and final lap.
The lap time was the fastest achieved by a F3 car in 26 years of the formula's racing at the stone wall and steel barrier-lined circuit.
Hartley's Carlin Motorsport team boss, Trevor Carlin, who has a relationship with Red Bull's junior programme, described Hartley as a "very valued and well-liked member of the team".
"He showed stunning pace in British F3 last year and towards the end of the season a new maturity and confidence emerged in his racing, which I'm sure we'll see again in F3 Euro Series in 2009."
Despite his achievements, the phone call asking him to front up for the F1 test was "a bit out of the blue", Hartley admits.
He dialled three numbers back home in quick succession - waking up his father, brother and New Zealand agent in the dead of night with the news.
It was confirmation of something Hartley says he has been working towards his "whole life."
"It's pretty special. Like I say, it's been my dream."
Did he have a rampaging case of butterflies when buckling up in the fastest car in the world?
Hartley says he was more nervous in some of his Formula Ford races - in the days before he became more adept at mastering the mental battle.
Despite having trained for it, the phenomenal velocity took some getting used to. And then there's the g-forces.
Under braking and around corners the car was exerting 6gs - "basically like being kicked in the neck" - and 4.5gs laterally.
"Your neck really suffers. It's the same for anyone who drives a F1 car for the first time."
Then there is the pressure of having 90 people in the Red Bull team involved with the car that day and the matter of the $450 million budget for the year.
"You try not to think about it but if you stuff up it's a big waste of their time."
Hartley not only kept the car on the track for the 83 laps but guided it to the third-fastest time that day, behind BMW Sauber team driver Nick Heidfeld and quickest-on-the-day Red Bull test driver Sebastien Buemi.
The 370km covered qualifies him for a FIA superlicence - his passport to test and race F1 machines - yet whether he receives one is not just about driving.
"It's about a lot of other things as well," he says, commenting on the internal politics Formula One is infamous for fostering.
The long-anticipated test day is now but a distant memory as the mind of an up-coming race driver must remain firmly funnelled towards the future.
Hartley is focusing on the start of Euro F3 testing in March and whether he gets his superlicence is out of his hands.
What can't help but be on his mind is whether he will be the first New Zealander since Aucklander Mike Thackwell finished up the last of five F1 race outings in 1984, to be a fast fern in Formula One.
Brendon Hartley's career path
Brendon Hartley looks at the race track before a training session for the Red Bull Racing Formula One team at the Circuito de Jerez in Spain last month.
2008
-Completed 370 testing laps in Red Bull Formula One car
-Third overall in British Formula Three Championship
2007
-Champion in World Series by Renault-Eurocup 2.0
-Third in Formula Renault 2.0 Italian series
-Pre-season Silverstone Grand PRIX circuit test session with A1 Team New Zealand
2006
-Offered Red Bull scholarship drive in its junior development programme, competing with a German team in the Formula Renault 2 litre German and -Euro-Cup Championships
Toyota Racing Series
2006: Winner of the Dan Higgins Memorial Trophy (February 19 at Manfeild)
2005: Winner of the first Toyota Racing Series race (Timaru)
2005: Won the Elite Motorsport Academy Award
Formula Ford
2003-04: Won six races and finished second overall in the Formula Ford Championship
2003: Winner of the Winter Series (seven wins)
2003: Winner of the Dan Higgins Memorial Trophy (youngest winner of the trophy)
2003: Youngest winner of a Formula Ford race (Manfeild, November 23, also secured two pole positions in qualifying)
Formula First
2002-03: 7th in series (12 years old)
