Wirelessly posted (BlackBerry8530/5.0.0.601 Profile/MIDP-2.1 Configuration/CLDC-1.1 VendorID/417)

Most credit cards that offer "secondary" loss coverage say that their coverage is secondary to any other collectible insurance that the renter has. If the renter has no other collectible insurance, then the credit card's secondary coverage is primary insurance for that renter. Some credit card's terms and conditions even say so explicitly.