If you are going to rent a car in Germany - please (PLEASE!), do not deal with Buchbinder!
Why? Here is our story.
We rented a car for 2 days, we returned it a bit earlier than was stated in the contract and - oops - the guy from Buchbinder found two scratches on the wheel rims.
BTW - have you ever returned a rented car? Most probably, you never saw such an inspection: the guy from Buchbinder touches with his finger every place on the car where he suspects he could find a scratch, goes further, then - returns backs and touches the same place for the second and for the third times ('what if we can say this is a scratch"). This happened to some three cars except for mine, inspection of each car took 10 min or more.
OK - finally they asked to write something in German (the guys had obvious difficulties with explaining in English what are we writing) and said something like "these are just scratches - should cost far less than 800 EUR" (our deductible).
But then, SMS says they charge 826 EUR. WHAT? This is at least more than deductible!
We try to call to Buchbinder by phone: no answer, just auto-reply. In email, we ask why do they charge extra 26 EUR (1) and if they really spend money and change wheel rims (2). 1 - Buchbinder ignores this question, 2 - kinda ignores (says that they will not show any receipt or the like, they just have the "loss estimate done by an expert").
Summary: with Buchbinder, you'll have to pay as much as possible (and even more than your contract says) for each and any scratch. And - frankly - common sense says that nobody changes the wheel rim because of a scratch. So the rental company can charge 800 EUR from the first customer, than - 800 EUR from the second guy if a new scratch appears, 800 EUR from the third one, and so on. After the tenth case, the company probably changes the wheel rim - and still, it has the used rim and can sell it for 1/2 of the initial price.
But wait - does every rental company do this? From our experience: no, the inspection could take less than a minute and in case of minor scratches they could charge some $30 or $100 but definitely not the full deductible amount. So simply forget of Buchbinder, rent a car in any other company (which treats their clients in some reasonable way) - and save your money.