bear in mind that modified car policies are very different to policy with mods added...
Firstly modified policies are often alot better if you make changes to the car as they dont bend you over if you do so mid policy.
But also importantly modified policies can be 'like for like' - which is important as if the car got damaged they would repair it to the same spec using the same modified parts. Eg you have a forge FMIC, they will repair it with a new Forge FMIC. whereas most companies that allow you to add mods are only covering any increase in risk that you now represent and not the modified parts. should your car need to be repaired it would be repaired to stock standards with stock parts.
(thats right, most insurance companies are charging you more simply as you now represent a higher risk as being someone that modifies their cars and not because you have better insurance that will replace modified parts should you need to claim).