Be aware that if you are using stand alone insurance the car hire company may wish to take a large ( £1,500 ) block on your credit card.When I picked up a car last year there was a very upset couple being pushed into buying the car hire insurance despite having stand alone insurance as they did not have a free grand and a half on their credit card.
Was that Europe or US? Never come across it but you can kind of see why. Maybe they do it surreptitiously when you are paying for the car, and it's never flagged up if you have sufficient credit available.