Have ordered these little gems from Ballards: See bottom of page

http://www.ballards.cc/Text/12028785...CATALOGUE-2008

Possible (and very cheap) alternative to the DNA stage 2 filter - or in addition to...

Also if drilling holdes in your airbox (ala Kevs mod) makes you nervous about water and dirt - these will also do the trick.

Will let you know how they pan out when fitted....