Glad we could help, the thing is with the K&N, although some will advise you it's such a small modification there is no point in declaring it, an insurer would be within their right to dispute a claim or ask for an additional premium to proceed with the claim but a point that most people disregard, you have a claim without the modification non-disclosed and you have a big worry on your hands whilst your insurers deal with it, will they find it? Will they void the claim? Much easier just to declare it and find a modification friendly insurer.
Ollie
Sky Insurance
http://www.skyinsurance.co.uk/modified-car-insurance.html