I got mine from AMS who used to do the GAP insurance at my local dealer. I was offered £250 for return to invoice over 3 years and £275 for vehicle replacement over 3 years. There is a benefit limit of £25K, but for that to be of any significance my car would have to be worth less than £7K or so within the term of the policy. AMS are a delightfully old fashioned company and dealing with them was very easy. With my previous cars, it was all done through the dealership so I'd never had any direct contact.