Anyway ... from all the expenses of a "round Africa" expedition... triying to save a few thousadns in the vehicle makes no sense.
Without starting another "how much dayly costs" thread ,
the Fuel , Visas, CarnetDePassage, Ferries , Hotels , workshopts , tyre repairs , tolls ,cadeaus , bribes , fines ,insurance for all that, and a few unknowns , for a roundAfrica will be greater than 6.000 Euros , probbably 10000Euros,.. So I can not see the point at all on using a opel corsa instead of a much more suiteed vehicle to save 1000 euros.
For a start , if the corsa is petrol , just buying a diesel landy is gonna save you 1000-2000 euros in fuel. Also , the Landy is much more sellable down there.