Difference between Audi in Ingolstadt and Neckarsulm?

What are the differences between the Audi factories in Ingolstadt and Neckarsulm? As in... which one is bigger, where are the most cars built, which factory does more design work, which one does more engineering work, and where is the focus of business?Difference between Audi in Ingolstadt and Neckarsulm?Neckarsulm is where the testing and some design is done, Inglostadt is headquarters and engineering