The most important priority before any trip is always to look at your car and be sure that everything is functioning correctly from your lights and indicators, to the windscreen wipers and tyres. If you´re unsure in regards to the roadworthiness of your car, get it looked over at any AA technical centre in South Africa for a small fee.
Also, it is important to have a couple of spares or tools with you, such as a spare car key, a pumped spare tyre, a jack and a puncture repair kit. Other useful things start adding some water and also a blanket, as well as a torch and spare batteries.
Don´t ignore the paperwork either, as if your motor vehicle insurance policy, emergency contact list and useful maps of your route, or your GPS. It is also essential to carry your driver´s licence along, that´s required by law.