You have to consider that Sky also charge each time you add a modification whether it be an increase in premium or an admin charge that should be factored into your quote if you intend to modify your car during the length of the policy and how many of us add all our mods in one go....not very many so this could lead to a dramatic increase, where as Greenlight don't do this they simply add them to the policy and with me it has had very little affect on the policy costs, they increased my premium by £40 for going from standard to stage 3 and then nothing for pushing it to 400bhp and then the policy dropped £150 this year come renewal time.
It is a little off topic as trackday insurance is being discussed but as it is being discussed then it's worth noting that we ask customers at quotation and renewal stage if they have any future modifications planned for mid-policy. If there are, we make the insurer aware of these and then no charge is made when the customer fits them. A lot of our customers take advantage of this, in fact I have incepted policies for two Focus's on this basis, today. I am sure the response will be, 'Well, I don't know what I'm going to fit' , that's fair enough, perhaps you do not, but most people will, or will at least have a rough idea.