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.

So how does a jet-lagged customer fighting through the language barrier at a rental counter survive these bungles? Some don't. They drive off in a car that doesn't fit their needs and/or wind up paying much more for it than they should have. The question you should ask is this: when you're at that rental counter does anybody "have your back?" The answer is 'yes,' provided you know where to book. Here's an illustrative story.

Skoda Yeti no Mercedes Benz

Fred showed up at the Munich Airport on a recent Friday expecting his guaranteed intermediate-to-fullsize upgrade would get him a Mercedes C-Class, Audi A4, or a 3-Series BMW. The counter agent, however, tossed him the keys to a Skoda Yeti, a Czech-made, RAV4-equivalent, SUV. Three weeks in the Yeti was not what Fred had in mind. Pleas to an on-duty supervisor were stonewalled ("sorry, this is all we have")—even though there were several Audi A4s and MBZ C-200s sitting idle in the rental company's parking lot. At this point Fred made an understandable mistake; instead of calling the Auto Europe 24/7 toll-free help line shown on his rental car voucher, he left the airport thinking he would resolve the issue later. Had he made that free call to Auto Europe, one of the always-on-duty reps in Portland, Maine, would have tracked down someone higher in the rental company food chain and quickly resolved the situation in Fred's favor.

Next morning, Fred was stiffed again when he phoned the rental company to request an exchange of vehicles. Still eschewing the toll-free help line, he called the Gemut.com offices. Though they are closed early on a Saturday morning, voice mail messages to Gemut.com's main office (option 3) are automatically emailed to an off-duty Gemut.com employee and, in this case, Fred received a return call at 9am PDT/6pm Munich time. After getting the details of Fred's problem, Gemut.com immediately contacted an Auto Europe weekend supervisor, who in turn contacted a supervisor with the rental company in Munich. Arrangements were quickly made for Fred to exchange cars. In fact, Auto Europe even paid for Fred's gas for the extra drive to and from Munich Airport where he at last drove off in a 2012 Audi A4 with satellite navigation.

So who's got your back at the rental counter?

The point of story is that one would be hard pressed to imagine this incident being favorably resolved had Fred booked online with one of the major online travel agencies or directly with the rental company itself. When you are being told at the XYZ rental counter that the promised (in writing) car category is not available, you need an advocate—one that has some "juice" with XYZ. Otherwise it's you vs. XYZ company and, by the way, how did that turn out for Fred? You see, he finally got the car he should been given in the first place because he booked through a partnership—Gemut.com/Auto Europe—that offers 24/7 customer service delivered by actual human beings. Does anyone know whom to call at Priceline if things aren't going your way at a Munich Airport rental counter?