European rental car companies sell their highest profit items to travelers who are in a rush-a rush to pick up the car and a rush to drop it off. As a rental car customer, you are vulnerable when signing the rental contract and upon returning the car; times when rental car companies make their biggest scores. By not paying close attention to what they are signing, and perhaps because they are tired and thus more susceptible to a sales pitch, renters often wind up with credit card charges far beyond what they anticipated. Most of the time it's not until they return home that they discover their signature authorized unnecessary and unneeded items such as collision and theft insurance already covered by their credit card. It's also a nasty surprise to learn they paid for an extra driver or an upgrade they thought was free. Perhaps they misunderstood, but maybe they were misled-keep in mind that rental car agents get paid more when they sell extras.

Returning the car is also a time of peril. In a hurry to get to the airport, and perhaps noting the fuel tank is close to full, some renters decide to let the car rental company top it off. That's what happened to Tom and Sally Ryan (not their real names). Running late to catch a flight from Bologna, they turned in their car 2.9 gallons short of full. Europcar charged e19.14 for the fuel and a scandalous e21.6 refueling service fee. At an exchange rate of 1.41 that is $57 for less than three gallons of gas.

But there's more to the Ryan story. Picking up the car in Rome they were aware of the mandatory collision (CDW) and theft insurance that comes with each car rental in Italy. On a seven-day rental they prepaid $392 for this insurance, with a e350 deductible for collision and a e500 deductible for theft. You heard right, $392 to insure a minivan for one week, not six months or a year. Of course, that price doesn't cover damage to the car's roof, undercarriage, wheels, tires, or interior. So when they got to the rental counter, they decided to insure against damage to those parts of the car at an additional e46.62. They also coughed up e63 to reduce the deductible to zero. Then there was something called "Vandalism Action Coverage" for e21. In total, the Ryans spent nearly $600 to insure a $27,000 car for a week.

There was one more small gouge visited upon the unsuspecting Ryans: Direct Currency Conversion (DCC). Asked if they wanted to pay their final e192 bill for these extras in dollars, the Ryans naturally said yes. This got them an exchange rate of about 1.45 instead of the 1.39 bank-to-bank rate they would have gotten had they insisted the credit card charge be in euros. So Europcar and the company that peddles DCC split about another $11 of the Ryan's money.

Verbal assurances mean nothing in the car rental business. When all is said and done, the rental is over and you're haggling about the charges, the rental company and your credit card company will rely on the written documents, not any promise made by an agent. Sue and Jim Morton (again, not their real names) picked up a compact car in May at the St. Raphael (France) rail station. The agent suggested that as a precaution, and since it was free, the Mortons add both their names to the contract. Though the rental voucher they were issued prior to leaving the U.S. said: "Additional drivers sign on and pay a fee locally," the  Mortons took the agent's word and signed the contract, which, of course, was in French. From a confusing list of possible fees listed on the contract-not all of which were to be ultimately charged-they failed to note the word conducteur (driver) at e29.6 ($42).

I can think of no other major travel purchase fraught with more minefields than renting a car in Europe. Nonetheless, the careful traveler can navigate through them. After all, an automobile is still the most liberating way to see the countryside and you can get a four-door car with air for a week in Germany for $244, including the 19-percent value-added tax and unlimited miles. For a couple, that's $17.43 per person, per day for flexible, comfortable transport that will take you whereever you want, whenever you want-and it's your very own space. A four-day, second-class German rail pass for two persons is $48.75 per day, per person.

Here are some suggestions for avoiding unwanted charges:

· Get it in writing. The agent at the counter is probably not a crook, but he or she may be poorly trained, inexperienced, and thus give you bad information. If you are told there is no charge for items such as an extra driver or an upgrade, make sure it's on paper. For example, if you are promised a free extra driver, ask the agent to write and initial the words "free extra driver" on the contract. Do not sign the rental contract until you know what you will be charged for. If you're uncertain, see "Have a safety net" later in this story (page 8).

· Know the terms of your reservation. Customers of Gemut.com are issued a voucher that guarantees the price of the rental in U.S. dollars and specifies what is included in the rental price and what is not. If there is a post-rental dispute over charges, this is the document that governs which charges made by the supplier are valid and which are not. However, if you choose to rent additional equipment such as ski racks, child seats, a navigation system or, as the Ryans did, purchase additional insurance, you can expect to pay in euros plus tax. These additional items are a main source of rental company profits.

· Have a safety net. Travelers who book with Gemut.com are given a free, toll-free help line that's staffed 24/7. If there is any question or confusion at the rental counter make the call. If you've booked directly with a rental company or online through the likes of Orbitz or Travelocity, you're on your own.

· In Europe, pay in local currency. Direct Currency Conversion, the financial device that entices visitors to pay in their home currency, is really just a way for retailers to make a few more euros, francs, kroner, etc. on each transaction. For the privilege of knowing to the penny what will appear on their credit card statement, they get a less favorable exchange rate and a built-in extra fee that experts say ranges from three to five-percent. Demand to pay any local rental car charges in local currency. The same goes for hotels, restaurants, and retail stores.

· Dispute overcharges. If you suspect you've been billed too much, call your credit card company and dispute the charge. You won't have to pay until the charge is determined to be valid. This puts the burden on the supplier. European rental companies are notoriously slow in responding to requests for post-rental documentation of extra charges. Their policy seems to be "charge now and answer questions later-much later." If the rental company has your money there is little motivation to respond. But that all changes when the credit card company denies payment or initiates a "chargeback."

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