I have ordered one of these, not K&N but the Jetex variety. Looks like recommendations for these replacement filters are mixed, but I'll give one a go and report back with any improvements in performance, or otherwise.
What I can't find on the web are instructions on how exactly to clean this sort of panel filter, and how often they need to be cleaned. There are instructions for other sorts of cloth filters but not the panel type. Some people elsewhere suggest cleaning every 5,000 miles, others 10,000, whilst the guy in the shop said every 30,000 miles. I should be grateful if someone here could give me some advice, or let me know of a definitive guide on the web.