A few years ago the public only had one provider to use insurance4carhire.com. Then along came along several more companies (some of which actually use insurance4carhire.com products and Questor insurance.)
The price that the car rental company is normally higher than that of these independents like insurance4carhire, Questor Insurance and Essential Travel. What is even more important is that if you rent more than once a year, it will work out a lot cheaper if you actually take out an annual policy from one othese insurance companies.
At the insurance4carrental.com site you have the choice of these companies: insurance4carhire and their daily excess product dailyexcess.com, Questor insurance, Essential Travel, iCarhireinsurance and Odyssey.