Know your destination's car insurance quirks

For example, in some European countries collision policies that car-rental companies sell typically do not cover stolen vehicles. (All agencies operating in Italy require that you buy CDW and a theft-protection policy, but those costs will already be included in the rates you are quoted). And Mastercard is one of the few American companies that offer Americans CDW in Ireland. (At the rental counter you'll need to present a letter from Mastercard stating that it does, indeed, provide this coverage, or you'll be forced to buy it.