I'd stay far away from the BMW. Unless you have lots of cash, of course.
The direct injection technology is still new ( relatively ). There is a class action lawsuit in the US being taken by some BMW owners against BMW on this.
IT's because of the HPFP (high pressure fuel pump). I know about this problem but it's very rarein SA. Most of the incidents occur in the USA and are caused because of the high ethanol content of their fuel. Here are some articles that I read about it: