Avis at Frankfurt airport conducts business in an un-ethical manner with scam! We booked the…read moreMercedes E class car through Costco travel in the US before we arrived Frankfurt. When we picked the car at the airport, they didn't have the Mercedes E, and upgraded to a Mercedes SUV. When we asked the price, the agent told us the charge will be the same price of ~$800 as what we ordered and asked us to sign documents with a higher amount for a deposit. When we returned the car, another agent charged us the price of ~$1,800! It is more than double than what we ordered! We tried to talk to the manger in the office, she did not consider the circumstance, but just simple told us that we signed the document. We have been with Avis many years, but we can not believe Avis at Frankfurt office mislead the customer to pay more than double price intentionally!!