There must be some sort of mistake there Dunk, I know you're only plugging it into go compare for an idea, but imagine when you contact them to discuss it'll be a different story (hopefully!). It may be that they've treated you as a new customer with the quotes and the change would just be an administrative one which should only attract a small charge. I know that when I sold my last supra and went to amend my policy for the new one (same year, same model, just different colour and reg) my company tried to charge me a fortune, it turned out that I got an 'experience' type bonus/discount for owning the car for so long (8 years) and I had to get a manager to agree that the same discount should apply for the new one.