I could be wrong, but my recollection has it that CDW is MANDATORY in Italy. This is one reason why car rates seem so high there compared to many other countries in Europe.

As far as using a credit card for insurance, I cannot concur with what has been posted here. Europeans have long been deprived of this most valuable protection. I know that the benefit is now available (In Germany for example with a Lufthansa credit card).

Insurance sold by rental companies is such a rip-off. They often earn more selling insurance than renting the vehicles.

I personally have a Diner's Club that offers primary rental insurance. If I DECLINE the protection when renting a car, I have a $0 deductible. If I buy the CDW I have a deductible that ranges anywhere between $200-$1000. Does that make any sense? You have LESS protection when actually paying big dollars for insurance.

The fact remains that one needs to be educated how these things work. Certainly, no one wants an accident. If you rent a car with a credit card providing insurance, you will have some work sorting out the paperwork which you won't have if you just buy the CDW. But in the one accident I had with a rental car, the credit card insurance kicks in pretty quickly once they have been duly notified that an accident has taken place.

My vote is to get a Diner's or AMEX with primary insurance, and decline any CDW offered by a rental company.