My big concern for you is that 10 days is not enough for the distance and time to travel there. Like anywhere you travel, be prudent. Most likely you will head out to a game reserve and you won't even think about it again. Cape Town is a lovely town and the South Africans are great people, but there is A LOT of poverty. Just be prudent and do as the locals do, you pay someone a token amount to watch your car, don't over pay or you ruin it for the next guy.