Originally Posted by
bocastephen
Very simple answer to your question - however, you should always confirm policy details with your credit card's insurance carrier, and your own private insurance company.
1. using a free day coupon or award, or a collection of coupons that results in $0 of rental charges on the contract (only taxes) - no credit card coverage whatsoever
2. using a free day coupon or award, or a collection of coupons that still results in one or more days of actual rental charges on the contract (ie, rent 5 days with 2 free days) - you should have credit card coverage
3. your private insurance does not care about coupons/free days
4. if you use a corporate code with LDW, then all credit card coverage is voided because the policy requires you to decline rental car company provided coverage, however in almost all cases, your personal insurance will cover damage and liability
I also believe that World Mastercards require 1 paid rental day for coverage.
also you must look at the maximum length of time a contract can be written. Amex says 45 days within the same geographical area. Therefore if you rent back to back with Amex, longer than 45 days, they may not cover you without a full calendar day break between rentals.