I have a 2006 astra 1.4 16v and i want a bit of a note out of it. I was looking at the K&N induction kit 57i for the astra, but after a bit of research i have seen that alot of people are sticking with the standard air box, de-restricting it and putting in a K&N pannel fillter. i am not realy intreseted in preformance at this stage. its really just for the sound. could any one tell me which one has a better sound thanks.