I rented a car from SIXT in Bordeaux for 3 days. When I returned the car, before flying out, they told me to just leave the keys as the only staff member was helping someone else (big mistake on my end!). A few days later I received an email saying that upon review they found a 10cm scratch on the rear bumper, one that I am pretty sure I did not cause but sadly have no way to prove since I did not take pictures when dropping off the car. The infuriating part though is that from the pictures SIXT sent me you can tell it's an incredibly superficial "damage" and there is no way anyone in their right mind would charge 414 euros for, which they are of course doing. It's clear that they don't have an interest in maintaining a loyal customer pool and are simply out to get you. I would STAY AWAY from Sixt. Plenty of other car rental companies around!