I'm afraid the Weissach / Flacht explanation isn't exactly correct. Flacht is the village, but it sits within the municipality (Gemeinden) of Weissach. Weissach is within the District of Böblingen; which is part of the State of Baden-Württemberg. People refer to the Porsche Motorsport Centre being in Weissach, and that is correct - but that isn't the town, it's the municipality.

Porsche Motorsport.
Village: Flacht
Municipality: Weissach
District: Böblingen
State: Baden-Württemberg

That is why Flacht and Weissach are referred to being the home of Porsche Motorsport. And both are correct.