Genuine OEM Audi Air Filter Housing Upper, part number 420133846AA. This part forms the upper section of the air filter housing assembly, enclosing the air filter element and ensuring a proper seal to direct clean air into the engine's intake system. It is located within the engine bay, integrated with the air intake ducting. Genuine OEM air filter housings are manufactured to precise dimensions to guarantee an airtight seal, preventing unfiltered air from entering the engine and ensuring optimal performance and longevity.