I am pretty happy with my CAI, it took me 3 months to research and decide.
Fit, quality and sound are right on. Install was a breeze.
As for price... SHOP AROUND. DO NOT PAY $399.
First time I mashed the throttle I loved the new growl.
Next is the bottle relocation/scoop and then headers and exhaust.
I have enough reading material that this will take me to next summer

Then Cam and headwork..... it will never end. Or maybe a ZL1....