Not sure which 2003 Audi A4 Air Intake Systems are right for you? We have over 15237 customer reviews, with an average rating of 4.5, to help you find exactly what you're looking for. Here's what some of our customers have said:
"Finally tried it. and I am SOOOO happy I did it..This is a great unit, you can feel the Difference!!BUT in order to really feel the Difference, you also want to get an Jet Power-Flow Mass Air Sensor and flow master!!!I am using all 3 units. I really can feel the power!! It feels like I have a race car now and not a MID-SUV.Use all 3 units you can't go wrong!!!If you just buy the K&N intake you wont to get that full power.Make sure you also get a new Flow Mass Air Sensor, because that stock Air Sensor won't give you the full power from your intake. The flow master is a plus to have.Thanks Again, Cello" —Marcelo D from Long Beach, CA bought a K&N 57 Series FIPK Air Intake (Fuel Injection Performance Kit) for a 2003 Audi A4.