K&N 01-09 Audi A4/RS4/S4 Drop In Air Filter

K&N's replacement air filters are designed to increase horsepower and acceleration while providing excellent filtration. We make over 1,200 different replacement air filters for the majority of vehicles on the road. These filters are washable and reusable and are custom designed to fit into your existing factory air box. Their drop-in design means adding performance is simple. With most vehicles you simply remove the disposable air filter and replace it with a K&N. See applicable instruction sheet for details. Our stock replacement air filters for street vehicles are covered by our famous K&N Million-Mile Limited Warranty and will be the last air filter your vehicle will ever need. K&N's replacement air filters are designed to increase horsepower and acceleration while providing excellent filtration. Our stock replacement air filters for street vehicles are covered by K&N's Million-Mile Limited Warranty. Fitment: Audi A4 Base 2002 to 2008 Audi A4 Cabriolet 2003 to 2009 Audi A4 Quattro Avant 2002 to 2008 Audi A4 Quattro Base 2002 to 2008 Audi A4 Quattro Cabriolet 2004 to 2009 Audi RS4 Base 2007 to 2008 Audi RS4 Cabriolet 2008 Audi S4 Avant 2004 to 2008 Audi S4 Base 2004 to 2008 Audi S4 Cabriolet 2004 to 2009