If you are wealthy enough you can always "Self Insure", go see a solictor stick 1 million in a bonded account (cannot be accessed, although you can still earn the interest off it) and hey presto your insured and no ins companies to pay or moan about should you mod or stay std
I only know about this as my mate knows someone who did it, he runs 4 cars on his "self insured policy" (him/wife and 2 kids). He must save about 8k per year in ins costs and it does not cost him a penny as he still gets the interest on his money, win/win.
Nice if you have a spare million!
For the normal folk, Mods=Declared, if not your a muppett!