Hmmm, that's odd...
I'm 35 and have declared my mods (CF Bonnet, CF lip and wheels) and pay £600 fully comp, if I recall correctly I have 6 or 7 years NCB (protected) and more points than you.
Mine is a '04 UK Coupe tho, so that prolly plays a factor.
You look good for 35 Mark
Yeah def shop around, im 25, declared my nismo wheels (covered for full value), suspension, brakes, exhaust, jwt. Got 3points and pay £550 ish
Just a hint, when getting quotes try adding someone older to the policy, like a parent, it brough mine down a huge amount for putting my mother on it, she has never driven any of my last 3 cars (and never will) but she has saved me a fortune