I don't know what criteria insurance companies use to decide how much to increase your premiums by... I'd guess increased desirability making it more nickable (upgraded ICE, etc.) and performance enhancers (remaps, exhausts, etc.) would be two main ones. I'd have thought ARBs, LCAs, etc. would count as performance mods too...
It doesn't really matter though; you should tell them about *all* modifications and until you have don't fit them to your car. Do you really want to wait until you need to make a claim to find out what you should have told them about?
Do they know about the chassis mods on your list?
http://type-r-owners.co.uk/forums/s...-*small-update-new-look-forum-graphics-pg-27*