Question from a potential customer: What can I do to protect myself from unethical conduct by car rental companies who can make any claim and charge my credit card after I am back in North America?

Answer: First of all, your credit card protects you against erroneous, improper charges. You can dispute any questionable charge and not pay it until the matter is resolved. The credit card company will require the rental company to prove the charge is correct. That usually means the rental company shows the credit card company a copy of the customer's signature on the rental contract, thereby authorizing the charge.

The suppliers Gemut.com deals with...more than 90% of our bookings are with Hertz, Avis, Europcar...are not unethical. Their employees, however, sometimes make mistakes and a tiny percentage may try to take advantage of unsuspecting and unprepared customers by selling them extra, unnecessary insurance or other services. Our customers are also protected by a voucher which establishes the charges as well as the rental's terms and conditions. In addition, if there are erroneous post-rental charges, we will deal with the supplier on the customer's behalf and obtain a refund. Of course, if the customer signs a contract at the rental counter that, for example, calls for additional insurance, that makes it a legitimate charge and no refund is possible. We urge our customers to be prepared for the European rental transaction by reading the advisory information at our Website. Download What You Should Know About Renting a Car in Europe (PDF).

Refunds for erroneous charges may be more difficult to obtain if bookings are made via off-shore online-based car rental websites and rental companies that do not maintain North American offices.

It is not possible to rent a car in Europe without the rental company blocking from $500 to $1500 (approximate numbers) on the renter's credit card. If the car is returned with an empty fuel tank, for example, the rental company wants to be assured of a source of funds to pay the additional charge due at the end of the rental. Nothing is charged to the renter's credit card but the block has the effect of reducing the card's credit limit by the amount of the block.

A puzzler for many a Europe-bound auto renter is how much luggage will the rental car's trunk hold?

7 Pax Van-Luggage for 6

Because rental companies guarantee by category rather than by specific make or model, a definitive answer isn't really possible. There can be small differences among vehicles in the same car category, including trunk size. To complicate matters further, rental companies lack consistency of size in their fleet categories. For example, virtually every rental company in Europe puts the Mercedes C-Class and the BMW 3-Series in the Fullsize category. Neither car offers the size or trunk space of the VW Passat, Peugeot 407, Renault Laguna, VW Touran, Opel Insignia, Skoda Octavia and several other Intermediate category rental cars that are much less expensive than several cars in the Fullsize category (wonder how many millions of dollars are spent by renters of Fullsize cars under the mistaken impression they will have more luggage space than an Intermediate car?).

Increase Your Chances for Getting the Right Car

Our best advice is to grab a suitcase or two and visit local car dealers. At your Mercedes dealer you can find out if that C-Class sedan (or similar) will really accommodate your party of four plus luggage or will your five passengers and their luggage work in an Intermediate VW Passat station wagon (unless you want to spend a really lot of money, it's just about the largest station wagon available for rent in Europe)...or do you need a seven-passenger van?

A couple of weeks ago we suggested a customer headed for Italy (where rental car prices are the highest in Europe), who was convinced he needed a Fullsize wagon for his two-week, visit his local BMW and Mercedes dealers. In doing so he discovered that Premium category sedan (BMW 5-Series or similar) would work better for his party of five than the Fullsize Mercedes C-Class station wagon...and also saved him about $500.

Of course, that ever-present rental car phrase “or similar” means you can never be 100% certain.

Click for info about rental car passenger and luggage space.

I know little about the business of high-tech digital gear, but I can guess GPS makers such as Garmin and Tom-Tom are having a rough go. Increasingly, people use smartphones for guidance when on the move. For example, I no longer rely on my car's factory-installed GPS. iPhone's Google Maps app is easier to program, has much better maps, better guidance, and the destination can be changed by my wife while I'm driving (our car has to be stopped in order to request a new destination on the built-in GPS).

Depending on what it will cost for data while traveling in Europe, you might want to rely on your smartphone's Google Maps app. Another option is to buy a cheap, used GPS.

Whatever you decide, you will want to think long and hard about renting a GPS from a car rental company. They are expensive and don't always work. Rental fees range in price from about €5 to €21 per day. Some max out at €90 to €200 for a longer rental. And what you get isn't always the greatest. Rental devices are heavily used and we hear complaints they sometimes don't work properly. Most are multilingual but many renters find they are unable to set them to speak English. To rent a car whose price includes GPS, you will probably have to book more expensive fullsize or higher category cars. Few economy, compact or intermediate cars come with built-in GPS, and seldom is the price include in the overall rate.

The only problem with using Google Maps on a smartphone in Europe is the cost of international roaming. However, you can probably purchase an overseas data plan that will allow you to operate Google Maps while driving (prior to a recent European trip I paid AT&T $59 for a 300MB overseas data plan which, by being judicious, I didn't use half of).

However, even if you disable data roaming entirely, you can still use Google Maps in a limited way. Before starting out on an auto trip, connect the phone to the Internet via WiFi at your hotel or a café. Next, set your departure and destination points and Google Maps will create the route. Once you are in your rental car, even though Google Maps won't have access to the Internet, it will continue to show your position along the route by using satellites and cell towers. It won't provide verbal directions and you can't change the route, but it will keep track of your progress.

Another alternative is buy a used portable GPS. Right now on eBay, you can purchase used devices that include Europe maps for as low as $40. A Garmin Nuvi 670 with Europe and North American maps, which a few years ago sold new for over $600 (I know, I bought one) has a bid price of $49.99 and 'buy now' price of $99.95. My Garmin 670 still works great but it sits in a drawer; Google maps on the iPhone is better and a lot handier.