Mine went up from(memory) about £450 to £1180, with privilege.
The same insurer has some new terms added, which I read and rang them, on the gf astra they added £80 due to a "modification", a toad C5T2, yes truly, they cited it wasn't approved, as I fitted it, and issued the cert,(as I was currently certified then).
A few calls later got a better quote, which they then matched.
They are robbing shits, most of this imo is not caused by any claims culture but the amount of non insured people, esp those having accidents.
The police are averaging(from their own numbers) between 450 and 500 a DAY getting caught driving without insurance, that's a day everyday.
These range from people with undeclared mods to people just thinking it doesn't apply to them.
As modifications go I think the insurance companies have a lot to answer, it is so unclear, my mate lee runs his own bodyshop, all approved etc, and saw recently a claim turned down as the car had a towbar fitted(damaged was front/wing from a deer), and a bmw 318 allowed that had had a 325 engine fitted, the insurer's rep spotted this and still allowed the front end damage, it was the same company in both cases, all they did was increase the premium for the bmw.
tabetha