incase you havnt tried them give brentacre a call, when i was trying to insure my gt adrian flux quoted me 2.5k on a standard gt, admiral 1700 on a standard gt and brentacre insured me all mods declared @ 280bhp for 1500 fully comp, i was 24 at the time but only 1 years no claims and there pretty sound lads that you speak with there they actually know about cars and the mods had a twenty minute conversation with them about mine and how fast it was