I quote Wikipedia:

• Walkabout is an Australian pidgin (or perhaps quasi-pidgin) term referring to the belief that Australian Aborigines "go walkabout" at the age of thirteen in the wilderness for six months as a rite of passage. They then trace the path of the ceremonial ancestors of their tribe, following the exact route that those ancestors took, and imitating in a fashion, their heroic deeds. The term is used in the film Crocodile Dundee among others. It is also a main theme in the book Mutant Message Down Under.
• This meaning has lead to a jocular modern usage, whereby someone who has unexpectedly wandered off to destination uncertain is said to have 'gone walkabout'. It can also apply to a missing item, for example, "Ainslie, have you seen my stapler? It's gone walkabout again."
• Walkabout may be used to refer to a person's desire to travel without a planned itinerary or set destination; the more common English term is wanderlust.

Now, Jonathan has planned--or not planned--three weeks of the above in his red sports car (Peugeot 406 coupe).  Hence the Driveabout.

Please find our 'plan' below:

No one really remembers how the name came about.  I suspect it's related to the question: which animal are you most like? 

I, Chantal, am Duck (ostensibly I walk like one), and Jonathan is Monkey (he eats termites). 

Or he may have to before the end of our 3-week Australian Driveabout.