As I walked past this car I had to smile at the sticker on the rear window. The word "gifappeltjie" can be translated as "small poison apple" - which I guess could refer to the small car on which the sticker finds itself, or perhaps even the driver.
What I found interesting about a "gifappel" (of the genus Solanum) is that it's known by the names "Apple of Sodom", "Devil's Apple", "Poison Apple" and a variety of others. Some sites indicate that it's a treatment for all kinds of ills, while others claim it can be used to poison arrows. I even came across articles claiming evidence that it can be used to fight skin-cancer.
It seems as though the exact effect is determined by the species of Solanum. So, unless you know exactly what you're doing, I don't suggest that you go experiment with the medicinal properties too readily. ;)