When I was in grad school, I walked past another student carrying a book with the title, Black Logic. I remember thinking, “WTF?”
The term "German engineering" is an advertising slogan rightly intended to convey exacting standards and the utmost quality. Aside from a few venues (such as Free Republic where PC is nearly nil), using the term "African Engineering" would result in banishment since it's perceived to be a racial slur. Think also of a term ending in "-rigged" oft-used in a similar manner.