"We were like, 'Hello! Is anyone out there?' No one was out there because no one knew about it."
They persisted with their fledgling radio station, moving the set-up into a spare bedroom in Harwood's house, broadcasting relentlessly.
Radio Piha was born.
"It just turned into this massive community station," says Harwood. "We had people doing heavy metal shows, sports shows. I did the Saturday morning run."
Around this time, another idea was born.
Bored at his day-job editing advertisements, Harwood had a thought. "I was like, 'How hard would it be to write a TV show? I didn't know how to write a script, or tell a story. I was meant to be working, so I sat down and wrote this six-part show called High Road."
One of the characters, a bit-part character and "loser DJ guy" called Terry Huffer, was based on Mitchinson, a television and film veteran who's had roles in many major local productions, ranging from Outrageous Fortune to The Hobbit.
"I don't think he'd actually seen what he'd written," remembers Mitchinson, who read Harwood's script and quickly fell in love with Huffer.
"I knew I could play him, I'd been playing these terrible bad men [but] I love comedy. I really wanted to do a comedy."
So Mitchinson intervened. "Mark came running across the property," remembers Harwood. "He yelled, 'Why don't we pull all the Terry stuff out and make that into a TV show, and make five more?"
That's exactly what they did, calling in favours from Mitchinson's friends in the TV industry to put together a short web series of six 10-minute episodes, based around Mitchinson's character Huffer, a washed-up rock star running a low-budget radio station from a campground.
Life imitated art. And art imitated life. They filmed during school hours at Piha Campground and whenever actors and crew were available. There was no money for wardrobe or makeup.
No one was paid. According to an IMDB estimate, High Road's first season was made for $2000. Harwood believes it was less than that. "I gave everyone $50 for gas. We ripped it out in four days."
From those humble beginnings, High Road has become the little web series that could. It became a cult hit locally and amassed a loyal following overseas, including fans in France and South America.
NZ on Air got on board and a second season was made in 2014. Two years later came the third season, the one that made headlines for scoring a cameo from Emma Thompson.
Yes, Dame Emma Thompson, the Oscar-winning star from Howards End, The Remains of the Day, and Sense and Sensibility. "We gave her £200, because we had to," quips Harwood.
All of this is a way of taking the long road to say The High Road is now a very big deal. That's thanks to the new season, a full eight-show order for full-length episodes from Lightbox, the first scripted drama show commissioned by the local streaming service.
"We absolutely loved the original web series," says Lightbox's general manager, Hema Patel. "It was a hidden gem with a great cast, wrapped in that special sense of humour distinct to Kiwis ... we wanted to give the series a new lease of life."
Debuting on Monday, the new-look High Road includes a far larger budget, full half-hour episodes, some familiar faces from New Zealand's music scene, and several major set pieces. Weekend is witness to one scene that includes a stunningly awkward rumble between Huffer and rocker Jordan Luck, arguing over who wrote The Exponents' hit Victoria.
What other changes have been made? "We have someone doing our makeup now, and clothes," says Danielle Mason, who plays Shona. "In the early days it was slap something on, use your own clothes."
"We did it by the seat of our pants in the beginning," agrees Mitchinson. "I just called in favours from all my mates. It was all an accident. We had this ridiculous thing ... it's just as daft as it's ever been but everyone's getting paid a little bit better."
It's a long road to the top. What would the top look like for High Road? Are there any more sudden ideas coming their way?
Harwood quips that he's still mulling over something Thompson told him when they were shooting season three together.
"She said, 'As soon as you're doing the movie, we'll come over," he says. "It's hard to turn Emma Thompson down, so we're thinking about it."
• The High Road's second season is available for streaming on Lightbox from Monday.
