I experienced the same fraud in Hamburg, Germany when renting a car. Even after telling the liar behind the counter that my Amex would cover insurance, she said “No, Dollar cars cannot be covered by Amex and I would have to buy the insurance”. Fing liars at the desk and a fraudulent company supporting this. Fortunately, I am an executive in a rather large company and can at least protect my colleagues from ever renting a car from ths “company” again.
There will be a rule in our organization by end of the week, that Dollar is not a rental company that we will reimburse any more.
Let them continue their scam – websites like this will correct the market and help getting rid of dishonest liars like this company.