I just finished 20, 000 Miles South: a Pan American Adventure by Helen And Frank Schreider (Doubleday, 1957) Although dated, it is a travel story about the authors' journey from the arctic circle to the southern tip of South America. What makes it so interesting is that they did the trip in a military surplus amphibious jeep (Seep). Its a good read that details how they interacted with the mostly friendly natives they met along the way as well as how they introduced the automobile to areas that had never seen one previously. The book is out of print but I see a lot of copies listed on Half.com and Alibris for just a couple of bucks.

Chris