Former airline executive Gunther Holtorf and his wife Christine left Germany in their Mercedes G-Wagon, bound for an 18-month tour of Africa but somehow, they kept on going and even after covering 500,000 miles, 74 years old Gunther, his wife and the G-Wagon are still going on strong without any sponsorship or factory but self-funded. On the road since 1989 and G-Wagen moves them on even today without any serious break down. And you know what, your exotic G63 or 65 would make them financially broke within days and would never move on. The olden W461 280 G-wagens were the …