MC definitely NOT cover Australia and New Zealand, even in the platinum version. I haven't checked the details of the World version yet.

I know because we are going there in March and I have checked all 3 cards coverages in some details.

Visa - mine are United Signature, and Schwab Visa (not a signature) - covers Australia and New Zealand, as SECONDARY. That is, Visa would cover the "excess" - equivalent to the deductible we are familiar here in U.S. You also need to jump thru some hoops to invoke this coverage.

The rental car insurance in Australia and NZ is an entirely different subj and a very complicated one that I dont feel it is adequate to discuss on this thread.

Otherwise, outside US the coverage is primary. Domestically if you dont have car insurance or your car insurance is liability only (no comprehensive coverage), the coverage also becomes primary.

Visa has a slightly better coverage in terms of what are being covered, and in the procedures required to file claims. For example, Visa covers Admin fee, if approved. MC excludes Admin fee altogether. The Loss of Usage charge while it said is covered on MC, it is near impossible to get it approved, eventhough the rental car is willing to provide the "fleet log" to sustain it.

We used MC coverage in Sept 2005 for a hailstorm damage to our Thrifty rental car at Yellowstone National Park. MC paid the Repair estimates, but shot down the Loss of Usage, claiming the proof provided by Thrifty was not sufficient. The Admin fee was not covered. (The Thrifty location at Jacksonville is a franchisee, and its insurance matters are handled by a 3rd party company located in Las Vegas!) We ended up paying the Loss of Usage and the Admin fee, totalling $320 after bargaining it down from $450. MC paid $2282 for the repair estimate. We chose to pay the insurance agent of Thrifty because they said they can file a claim against us, and potentially turn this to collection. For $320, it is not worth the hassle of fighting this and risk having a blackmark on the credit report. Besides, from what we saw at JAC, the rental car companies enjoyed very brisk business - if you dont have reservation, you basically out of luck trying to rent as a walk-in. Therefore we felt the Loss of Usage was a legit claim.