According to Dirk, the couple are undertaking this arduous trek because they wanted to have a long holiday, but couldn't figure out where to go, deciding, in the end, to see as much of it as they could.
During the trip, Dirk and Trudy are raising money for SOS Children's Villages, an NGO that helps abandoned, orphaned and destitute children throughout the world.
In the family since 1997, the Regter's 1915 Model T is powered by a 3.0-litre petrol engine and, aside from the larger and more comfortable tyres, is stock standard right down to the wood spoke wheels.
The journey began back in the northern summer of 2012 when they set forth from their home in Edam, the Netherlands, through France, Italy, Greece, Jordan, Egypt, Sudan, Ethiopia, Kenya, Tanzania, Mozambique, Zambia, and Botswana, before finishing up in Cape Town, South Africa.
In total, their first leg took 180 days to complete, with the couple covering 22,000km.
They followed this up in 2013 with a 28,000km grand circuit through the United States and Canada, starting and finishing in Houston, Texas, and visiting Los Angeles, San Francisco, Calgary, Winnipeg, Chicago, Saint Louis, Detroit, Toronto, Ottawa and New York City.
In 2014, Dirk and Trudy completed a 26,000km journey through South America, starting off in Columbia and then heading through Ecudaor, Peru, Bolivia, Argentina, Chile, rounding through Cape Horn at the bottom of the continent, heading back up to Uruguay, and ending up in Sao Paolo, Brazil.
During their many thousands of kilometres on paved and unpaved roads, the Regters were able to perform most of the repairs themselves. After they returned home, the Model T was hit by another car on a Belgian motorway. Although no-one was hurt, the car suffered severe damage.
If repairs can be completed in time, the couple plan on starting the final leg of their round-the-world trip in 2016. The current itinerary starts off in New Zealand, and goes through Australia, Indonesia, India, and crossing the Himalayas into China. Some time in 2017 they will make their way back to the Netherlands via Central Europe.