I just wanted to provide some up to date info here. In the past I was able to use my US Airways World elite Mastercard for rental car coverage in Ireland. On my recent trip last month when I called up to get the coverage letter, I was told the card no longer provided coverage.

Fortunately, I was able to confirm with my Chase Ink business card that they now provide primary coverage internationally including Ireland. They sent me a letter and I had no issues renting with Thrifty at DUB.