Met Gordon Murray and yes he is a clever engineer - designed the Maclaren F1. But he isnt clever real world. The income of an average african peasant is £400 per annum and he has to feed himself wife and lots of kids out of it. Even if someone gives him an Ox he cant afford to run it. Thats why he uses animals for haulage - they cost little or nothing to run and you can eat them if necessary.
A prevous inventor invented a cheap pre fab hut for africans and again that foundered on the same issue. It all smacks of Clive Sinclair.
What the poor africans need is a way to earn a better living ie markets in the west paying a fair price for their products. They need wells. They need very simple very basic machines. £10 to £15 k isnt cheap even for us.