Do we need passports?

Having just returned from Namibia last month ...Yes you need valid passports, and adviseable to take all vehicle registration papers or copy thereof. There is a vehicle road tax payable (we paid N$ 220 for 3 weeks). Have your drivers liscence always as they do have police check points occasionally. Borders were easy with the politest customs officials we've ever dealt with. Most borders operate 7am to 12pm, with major borders being open 24/7. Just check them out. Max Holiday duration is 3 months. Roads are good to very good unless you choose specific 4x4 routes. Tar roads between major centers, but gravel roads are good with continual grading maintenance being done. Maps 4 Africa travel map proved most informative. Good luck and enjoy.