WELL . any car with the steeringwheel at the right is more difficult to sell. Don't know if its forbidden or not . but in any case .. your vehicle will still be valuable as parts-donnor
In Gambia .. Customs' doesnt stamp your car details in the passport , so you are free to sell it /chop it / abandon it , etc....
There's a little hassle a the north-Senegalese borders..for cars over 5 year old.. without a carnet . You will be required to -either going in a Custom's escort convoy (?) at 225 Euros per convoy (of up to 3 vehicles)
or bribe your way out in Diama (bribes range from 50 Euros to 150 Euros).
Either way IT is definitely possible going thought.
Indeed if you are driving a car so obviously for sale , you could face a bit more trouble at Gambia's border.. but nothing that a couple tenners' bribe can't fix.
Fliying back from Gambia costs' around 300 euros one-way to either Madrid , amsterdam , London (difficult) , There are always some sort of good deals in tickets. Just shop around