Unfortunately, this seems to be a somewhat regular Sixt business practice. See
Zurich Sixt false claim of damage (which is not limited to experiences at Zurich).
Originally Posted by
janehoya
This is why I always walk around and video the car when I pick it up and drop it off.
That's not going to help at all with this particular scam. The only way to avoid it for sure is to stop renting from Sixt.