First I had The Neuspeed P flow
The I stepped up to the AEM CAI
After that came the Carbonio CAI
In the end I did a swiss cheese mod to the factory airbox with a K&N drop in.
The sound was louder with the open air intakes but like I said b4
HP gains were insignificant. maybe 3 to 4 HP
It will vary depending if you are at the wheels, crank or ecu
but only minor gains come with an open element intake.
However match the intake with a flow thru exhaust and you may see double digit gains. I got 17 with a milltek cat back and the Carbonio.
Add cams, a good chip program and you're getting somewhere.
But in the end if you're not racing the car to me you're better off leaving the car alone.
Just my .02