Our AAN engines use a large paper air filter that lives in a large airbox that is fed cold air from the front of the car (just under the edge of the hood). Info about the airbox, including the PN for the elusive airbox/MAF cover, is shown here



Some people switch to K&N filters based on previous non-turbo experience. However, with this engine, the gains are minimal and there is a danger when the filter is re-oiled that too much oil is added. This gets on the MAF hot-wire and causes grief. Better to stay with an OE Mann or Mahle filter like this one:



Available from the dealer and the aftermarket like Autohaus AZ