insurance cover

Hey guys. Going to be getting an fn2 but its got a toyo sports decat pipe.I believe thats literally the only mod. I've owned the 1.8 in past but had no mods,so its unknown territory for me. I literally know very little about exhaust systems/etc. I'm guessing the decat isn't even legal to pass...

I just would like to know how many of you actually inform your insurance company if you do minor upgrades like body kit, alloy wheels, suspension or anything that your insurance should be informed about, I dunno what to do about informing my insurance of the spring upgrade as technically the car...

Is the 12 months annual cover the car industry standard for the length of cover? If you have cover that you pay quarterly, who are you insured with? Reason: I may be moving to a job abroad in month 9 or 10 of the cover so would not need the cover for the remainly 3 or 2 months. However...