Buying a car
If you are staying more than a few months you might consider buying your own car. If you work for an international organisation like UN or an embassy you will be able to buy a duty free car, either from somebody selling their duty free car second hand, or by importing one. To be able to get it duty free it must be purchased within the first three/six months of your stay! Also, there is a lot of paper work to be done, which your organisation should help you with.
To help you find a car, you can look in TheExpatriate.org Motor Dealers on the service pages, the daily Nation or Standard newspapers, the weekly ADmag (free, every Friday), notice boards in shopping centres/organisations, or go to one of the car sales around town.
If you are buying second hand, and are not an expert in cars, it might be worth spending money to get a garage to test drive and look through the car you consider buying. They might discover if the car has had previous accidents, or if it has other serious problems. If not, at least they will probably say a few small things that need to be fixed, and thus give you a good starting point for negotiation of the price.
When you buy a car it should be registered with the Registrar of Motor Vehicles at Nyayo House, Tel. 33 33 88. For the registration you need the vehicle Logbook, insurance cover, certified copy of National Identity card of vehicle owner or a valid passport, and your own Personal Identification Certificate Number card.