I work for Europcar Adelaide airport in Australia and the amount of credit card fraud in regards to danage would make al Capone gasp.
They are thieves and I can honestly say that the Australian company as a whole is sick with criminal behavior.
ALWAYS TAKE PHOTOS OF YOU RENTAL CAR, ALWAYS MAKE THE STATION MANAGER INSPECT THE CAR BEFORE LEAVING THE CAR PARK
Otherwise they WILL charge you for damage whether any is done or not.