Renter's who don't read the fine print when booking a rental car in Germany with Thrifty or Dollar may get a nasty surprise at the rental car counter. The text below is just one important clause in both companies' terms and conditions. (LDW/loss damage waiver refers to collision and theft insurance.)

To decline LDW, customer must have US issued Gold/Platinum MasterCard or Canadian issued Gold/Platinum Visa Card and provide WRITTEN PROOF issued BY CREDIT CARD INSURANCE COMPANY that the card has FULL COVERAGE for GERMANY or WORLDWIDE at time of rental. Only US issued Gold/Platinum MasterCard or Canadian issued Gold/Platinum Visa can be used to waive LDW coverage. These cards will only be accepted for coverage for rental periods of less than 28 days in any calendar year. For 9-seaters, Credit Card Coverage is NOT accepted. If relevant card AND cover letter are not produced at time of commencement of rental then Dollar LDW must be purchased. In the event of an accident, any damage or theft, whatever the cause or who is to blame (even if the car was unattended), the driver must obtain the relevant report from the German police. Failure to provide a correctly completed police report to the rental agent on return of the vehicle will void the Loss Damage Waiver (LDW). The driver will then be liable for the total cost of the damage up to and including the total cost of the vehicle. Location does NOT accept insurances purchased on third party websites.

So, if you have a Visa or an American Express card (even Amex's Premier Car Rental Protection plan), you are out of luck if you had planned to rely on their free LDW. Instead, you will have to purchase the insurance at the rental counter, adding anywhere from about $13 to $25 per day to the rental cost. Renters should also know that most MasterCards do not cover collision or theft insurance on rentals longer than 15 days.

MasterCard rental car coverage terms and conditions.

Visa rental car terms and conditions.

Best Coverage: American Express rental car coverage terms and conditions.

The folks who staff auto rental counters screw up once in a while. They aren't alone. Sometimes the agents who book rental cars, as well as the executives who figure out how many in each of a couple of dozen car categories are needed daily at the perhaps 5,000 rental locations across Europe, also screw-up. It's been that way since 1916 when a Nebraska guy named Joe Saunders began renting his Model T Ford to visiting businessmen, and our guess is it will be that way 100 years from now when cars drive themselves.

Despite the many technological gadgets on new cars these days, it is still possible to lock the keys in a rental car in Europe. If that happens to you, phone the rental company's 24-hour road service, or call a locksmith. Do not do what Sam (not his real name) did recently in Oslo, Norway, when he discovered the keys locked inside his midsize station wagon. To retrieve the keys, Sam decided to break one of the car's side windows. His way of dealing with the problem was a quick and relatively easy solution, but shockingly expensive. Things are expensive in Norway (an intermediate sedan at the Oslo Airport is about $670 vs $240 for a similar vehicle at the Frankfurt Airport) but Sam never dreamed the bill for a broken window would come to a whopping $3,500. At this point we haven't seen the damage documents from the rental company so we don't know if there was more involved than just replacing the window.

Here's a tiny mistake that, in the process of renting a car in Europe, could cost hundreds, even thousands, of dollars. You have a pre-paid rental but there's a small vehicle license fee that must be paid in Europe. You reach into your pocket and hand over the few euros required. If you are relying on a credit card to cover the collision (CDW) and theft insurance, you've just canceled the card's insurance protection. For the credit card's insurance to be valid, you must pay for everything on the rental invoice with your credit card. The other two credit card requirements are that you decline the rental company's offer of insurance, and that you advise the credit card company of damage to the car within the required period of time.

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