Price quotes from most Europe-based online car rental brokers include vehicle insurance. This coverage is usually referred to in Europe as Loss Damage Waiver (LDW) and includes theft insurance as well as damage to the car. In North America, the terms are Collision Damage Waiver (CDW) and theft insurance. Unfortunately, in the fine print of these quotes one invariably finds that the included LDW-CDW/theft carries a high deductible or "excess," typically from €500 to €5000. This prevents the renter from relying on credit card insurance as that insurance is usually "secondary," meaning the credit card won't provide coverage if the renter has other insurance. In other words, under these conditions and terms if there is damage to your vehicle you pay the deductible.
In recent years, several overseas brokers, no doubt recognizing that North American buyers want "zero deductible" insurance, have begun to advertise "no excess" or "fully refundable excess." They promise that if your your rental car is damaged or stolen, and have to pay a deductible/excess fee to the rental car supplier, the broker will refund your out-of-pocket. Maybe.
