For me it as a bogus $48 fuel charge that appeared on a revised invoice days later, and yes it put me on the DNR after disputing it when they ignored my request to credit. I dealt with some really nasty billing people that were accusing me of doing something wrong when it was 100% Hertz's fault. Left me with an even worse opinion of Hertz. I already steered 95% of my business away to National years ago. I'm likely going to make Avis my secondary provider now and kick Hertz to the curb for good.