hey mate,
try the 3A racing pod, i know it looks cheap shit, however autosalon magazine did a test on 10 (i think) air filters, apexi, trust etc. And this came 1st in flow and 2nd in filtration. Wiped the floor with nearly all of them.
http://cgi.ebay.com.au/3A-Racing-Power-Sta...1QQcmdZViewItem
zac