From the BBC site: Back in 1989, as the Berlin Wall fell, Gunther Holtorf and his wife Christine set out on what was meant to be an 18-month tour of Africa in their Mercedes Benz G Wagen. Now, with more than 800,000km (500,000 miles) on the clock, Gunther is still going.
The best part about this is the quote in the video here about how he "did this under the radar". So many incredible overland journeys are well-documented, sometimes realtime, this guy is just doing it for the sake of doing it. Since his wife passed away from cancer in 2010, he's also been doing this journey alone. He plans on retiring next year, in addition to retiring "Otto" to the Mercedes-Benz Museum in Stuttgart.
Definitely click the BBC source below for a great video about it, I can't seem to embed it.
Sehr Gut Gunther.
Gunther Holtorf talked about his Africa hyena experience from alubavimeo on Vimeo.
Sources -> http://www.bbc.co.uk/news/magazine-18910560
& http://jalopnik.com/5929390/this-couple-took-a-500000-mile-road-trip-around-the-world & http://business.inquirer.net/62233/globetrotting-german-logs-800000-km-in-23-year-trip