The 28th Outback Car Trek began on June 3 and visited about 900 towns and villages across NSW. Organisers hope it has raised about $1.5 million for dental services.

Morgan Parker was among the entrants that set out from Griffith in one of 70 pre-1978 cars, which were specially reinforced for the journey and came with a support fleet of 20 vehicles to get them over the line in Port Macquarie.

"This is my fourth year in this event - it all started because of my father," Mr Parker said. "He had heard about it and thought it would be such a great cause and experience, so we bought a 1970s Holden Brougham with my brother and brother-in-law and started trekking."

Mr Parker said the experience not only raised money for the Royal Flying Doctor Service, but also allowed people to experience the outback from a different perspective.

"You get to meet the different characters out there and hear their stories."

Best known for outback emergency retrievals, the Royal Flying Doctor service also aims to reduce the well-documented gap in health and wellbeing between those living in remote, rural and regional areas and those in cities.

"We are proud of our long association with the Flying Doctor," Outback Car Trek organiser Bill Patrick said. "It gives Trekkers a real connection to the cause they have supported for so long and they will hear firsthand how the money they raise supports health services in regional, rural and remote areas."

Senior co-ordinator of community fund-raising Prue Steel said the event was "crazy - but great fun".

"It's really great to see so many people who are willing to help other people who don't have easy access to things as we do in the city," she said.

"There were a few breakdowns but that was all part of the experience."