Just spend 20 minutes on the phone with K&N and they say they don't have a product they endorse/recommend for a 2006 911 S4 3.8L. So in theory, my options are limited to Fabspeed ($837)and Evolution Motorsports ($595). Anyone have any first hand experience with either? I did see someone post a picture of their Fabspeed. Thanks.

 

The 996 kit works just fine, but you need to buy a cap for the vacuum tube that comes off the airbox. It sounds great alone, but even better with my Fister exhaust. When I just had the K&N, I had to really get into the 6k+ RPMs to put a smile on my face. With both mods, the exhaust sounds great low and mid and the intake really takes off at the high end. No power gains.