I originally wanted to drive around the continent like ONS4 who managed to drive around the continent with 2 young kids but after some calculations decided to base myself out of Dakar. Dakar would also provide decent surf when i was in town and not on the road exploring.
I found a place where i can stay for cheap in Dakar and borrow a Toyota Landcruiser for local use so i can get around alright. From Dakar I can fly to most of Africa either by Johannesburg or through Paris (much more expensive). Flights from Dakar to Capetown through Johannesburg cost around $1300 round trip on South African Airlines and its about the same for most flights through SAA. Through Paris the prices triple or double.
My plan is to use local transportation as available: trains, buses as well as rent a 4x4 for the trips along the beach. It looks like Hertz has the best rates so far and have the most locations around the continent.
My rough plan for my first trip after arriving in Africa is to fly down to Johannesburg, take a train to see the countryside to Capetown, then rent a car and spend a couple weeks driving the coast from Namibia to Mozambique stopping to surf where ever it looks good, then take the train back from Durban and fly back to Dakar.