When you rent a car, you are routinely offered a loss-damage or collision-damage waiver.  Do you need it?  The answer depends on whether you already have auto insurance and what it covers.  If you have collision and comprehensive coverage, it probably will pay for repairs but may not pay "incidental" rental company costs, such as loss of use, loss of value, and claim processing charges.  Many premium credit cards also will supplement your coverage, but you must use the card to pay for your rental and decline the loss-damage waiver.  To be sure, read the fine print of your insurance and credit-card agreements and ask any questions concerning them before you rent.