Renting a car is the best way to behold the beauty of South Africa but...
South African public transportation cannot be compared to that of developed countries. Taxis are scarce, and there is no public transportation in the country. The Gautrain operates in Johannesburg and Pretoria, while Uber is available in all major cities. Renting a car and going on a road trip is your best bet, but keep in mind that South Africans drive on the left.
If you do decide to rent a car while in South Africa, choose for a basic model rather than something fancy. Even if you can afford the best, this is not the place to flaunt it.
Because many of the people you meet will be poor, you'll have a larger probability of being robbed. Always choose a vehicle with a roof when purchasing a vehicle. This will lessen the likelihood of being robbed. Driving exclusively during daylight hours is also a good idea. This is one of the Things to Know Before Traveling to South Africa.