I recently bought a Mercury Marauder air box for my Grand Marquis, which is a popular modification in the Panther scene for the 80 mm MAF that comes with it. This is the factory air filter that came in the box:
You can tell this is a factory filter by the part number - 3W33-9601-CA instead of the service replacement, which is 3W3Z-9601-CA.
I remember reading about how different filters are installed at the factory, sourced from different suppliers. But I wonder if Mann also manufactures the Motorcraft filters for Ford? Ironically, there is no Mann air filter available for this application (2003-04 Mercury Marauder).
Call me crazy, but I'm keeping this filter. Going to put in a Motorcraft FA-1805 when it's installed on the car. Real shame a Purolator PureONE air filter isn't available for this application. That filter did an exceptional job of keeping dust away from the intake. With the other filters I used, there always used to be traces of dust in the intake tube.

You can tell this is a factory filter by the part number - 3W33-9601-CA instead of the service replacement, which is 3W3Z-9601-CA.
I remember reading about how different filters are installed at the factory, sourced from different suppliers. But I wonder if Mann also manufactures the Motorcraft filters for Ford? Ironically, there is no Mann air filter available for this application (2003-04 Mercury Marauder).
Call me crazy, but I'm keeping this filter. Going to put in a Motorcraft FA-1805 when it's installed on the car. Real shame a Purolator PureONE air filter isn't available for this application. That filter did an exceptional job of keeping dust away from the intake. With the other filters I used, there always used to be traces of dust in the intake tube.