Fontal,
mainlinemenace isn't quite right here.....
I have john's old HKS pipe, and a pipercross kit on the car, and i chose to declare it to my firm....it cost me 30 quid extra for the year, but i thought it was worth it for the extra piece of mind.
I had race cans on my bike, and never declared them...i think that insurance firms only tend to consider them if they think that the mod was contributory to the accident / incident.
i.e it could be argued that that a nice set of aftermarket alloys make the car more attractive to theft, so therefore nondisclosure may cause problems then,
it could be argued that zorst or induction kit add power, therefore change the insurance rating of the car...
Why don't you get the old pipe back on B4 the assessor comes around...or is it too late? Has he already noticed it?
Let me know whats happening
gerry