They are the same corporation for decades now. It's just that Audi is more iconic than VW.
But if I am not mistaken, there is a massive VW factory at Wolfsburg, right?
Yes, VW is the 2nd biggest car company in the world, Audi one of their brands, probably the most popular one and one of the most prestigious ones.
The big Audi plant is in Ingolstadt and they also happen to be the big sponsor for the local team, currently on their way to push into the 1. Bundesliga.
The big VW plant is in Wolfsburg ofc.
VfL Wolfsburg are often called "VW" since they are essentially owned by them, just like Ingolstadt is by Audi. If you want to call a football club "Audi", it's gotta be Ingolstadt. That's why I felt the need to clarify...