We rented a mini van from thrifty in frankfurt airport, germany May 2011 When we got there, we had our own premium car rental insurance from american express, they rejected it. They said we could only buy insurance from them, otherwise, they won't let us drive out their car. Leave no choice, we bought the super expensive insurance from them, which was 25 eur a day. The trip was going smoothly, nothing happened to the car, after we returned it to their parking lot, there is no person around. We dropped the key and went to their... read full review »