Personal Choice for me would be Green Air Or Apexi
I Have a hatred for K&N but i think that just cause thats what all the little numpties hear of first and their ever exagerated "performance enhancements" claims have turned me off them.
Im goina be takin the rest of my standard Air Filter housing out soon.... Only the bottom half of it in the car(the way i bought it).
Should be better able to explain how it goes in after that....