I have learned that Master Card world is accepted for Ins in the countries of Ireland and Isreal.Those are the 2 countries that give u a hard time.As far as rental days the most a credit card will cover is usually 28 or 30 days.The Master Card World covers 31 days. Rental companies will ask for proof so get it in writing prior to leaving. I suggest making rentals in several different countries., with the same company so you can drop the current car and get the new one and go. If you are an American traveler I found a great rental agency that gave me the dirt cheapest rental in Ireland for 31 days but I have to have a letter from credit card company that hey will cover 31 days.Silly in a way,the 31st day I am returning the car in the early morning but anything after 12AM midnight is a new day wherever u go in this world.
here is the link in case u want 2 check it out! Happy Travels!!

all the way:)
Auto Europe Discount Car Rentals, Airfare, and Hotels
Specializes in European car rental, air and hotel reservations, and cellular telephone rentals.
www.autoeurope.com/