I could be wrong, but I was under the impression that all credit card rental car coverage was secondary to one's own auto insurance policy (w/ the exception of Diner's Club). In other words, if the car rental company wants to blame you for damage they find, you have to submit a claim to your insurance company first and possibly recoup the deductible from the credit card company OR pay all costs out-of-pocket. With the way insurance companies operate, I don't want to file a claim for which I'm not at fault.