I'm resurrecting this thread as the Frankfurt Hertz station is adding dubious charges to the bills again. Damage claims for "scratches to tires" for $1500 appeared after returning a car and saying that there were no issues. No luck trying to contact the office either through phone or the email provided. Charges pending on credit card, with an email asking the credit card insurance to pay.

This is a pretty clear scam IMHO.

AVOID Hertz Frankfurt at all costs.