I'm with Adrian Flux. My 350z was double the price to insure than my Legacy B4 RSK which is a Japanese import twin turbo.
I think unless your car is pretty well modded or an import, they can't really compete, I guess a stock UK zed is just a 'normal' car and that's not their specialty.
Saying that, all the regular insurance companies like Admiral etc all wanted over 400 for the zed which surprised me a lot. (not in a good way).