generally speaking ... you do not need a carnet if you travel via the west Coast .
Some countries in the East (Egypt , Kenya , Tanzania ) still requires the carnet.. so It will be a lot more difficult .
I am driving to SA via the west coast (Motorcycle currently in Niamey ) without any intention to adquire a carnet. As far as I know if you follow the classic
morocco , mauri , mali (Senegal , Gambia , Senegal ) , Burkina , -niger , Chad , Cameroon , Gabon , Congo , Congo , Angola , Namibia , SouthAfrica
you can cross Africa without a carnet.
DISCLAIMER !!! This is what -I believe .. to the point that I am doing it . Things and regulations in Africa can change from one day to the next .Borders may be closed , or new goverments start requiring again the Carnet (althought the whole carnet thing is bein phased out in Africa ) things may change . I know at least 10 -12 people which made it to SouthAfrica without a carnet following this route .
however , there are people which for any reason they tend to fall into all sort of tricks/scams. in most borders in central africa they are going to rip you off , asking for any sort of paper (Carnet , special permit , central-african insurance, etc.. ) Its just a ripoff. If you dont have a carnetdepassage .. you need to pay ... but if you have , then you need to pay for other imaginary permits or rules.
Laws in Africa are not like at home , in which rules are respected , followed and enforce. Laws in Africa (other than Morocco ,and Egypt) are "blurry" , and even that a country states that they require carnet -such as Ghanna- , most people make into it without one.
Crossing borders without the correct papers (carnet , insurance , even vehicle registration ) requires some sort of "face value" -[cant translate this better into english , sorry ]-
some people made it every day into Senegal without a carnet , and some other fellas have their car nearly impounded in Senegal for not having a fire-extinguiser.Some people are ignoring passavants expiry dates with no consecuences , and some other people , are pullover and pay huge fines for not wearing the seat belt .
I can tell you stories of 2 britons , got into mali with a WV polo , nwithout even doing the border stuff ,no passport entry stamp , no visa ,no passavant , no insurance , and maybe even not registration paper or the car , they stayd up to 15 days in mali , got pullover 10 times by the police , and they dint have any trouble at all other than paying small bribes. On the other hand , you will find people which affirm that you enter a country without all the entry stamps , paperwork , visas, etc.. and you probbably end up in the Jail .
well, have a nice day