Not sure which 1999 Audi A4 Air Filters - Custom Fit is right for you? We have over 14143 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:
"I had been using a K&N since the car was new, and with the TAP Stage-1 chip upgrade. After a few recharge kits with the K&N, it just seemed to be lacking the power anymore. It was time for another wash/recharge (every 30k mi.), so I decided to try the Green filter this time. Maybe it was just because my K&N was really dirty, but I swear, I gained at least 10HP, possibly more. It was like a new car. I've only had a it a week, and still pulling hard, so time will tell. Highly recommended." —Jason K from Thousand Oaks, CA bought a Green Air Filters for a 1999 Audi A4.