I've just read the rental terms for Australia
https://images.hertz.com/pdfs/RT_FULL_AU_EN.pdf and I don't think this gives the the right to charge the processing fee for passing on notices of fines. It is badly written so it is difficult to tell. It says "We will work with authorites to pass on notices of fines and parking charges to you, and also charge you the Processing Fee." What exactly does this mean? Is it enforceable?
The only thing which could have been worded better is that "the processing fee" might be better as "a processing fee" but that doesn't really affect whether there is some sum of money due.