Just an update:

I got the airport and they gave me an Audi A8. Obviously this wasn't going to work since I need the trunk space, but eventually they found me an Audi A6 Avant with 2000 km. For the preinspection, I pointed out all the dings and scratches, and the lady didn't check and just signed off on them. As for returns, it was pretty easy and no hassles, and so far didn't get charged anything weird.