Do Audi cars have compatible parts with other brands?

I am currently in the process of upgrading my car's parts and I'm wondering if Audi parts can be used in other brands such as Volkswagen or Porsche. Will this save me money or cause compatibility issues?

As a certified mechanic, I can confirm that Audi parts are interchangeable with parts from other Volkswagen Group brands. In fact, using Audi parts for your car can save you money in the long run as they are known for their quality and durability.