I can’t think of any business where suppliers add on so many different fees to the displayed price you have to pay. And despite the notoriety of hotel resort fees, I believe car rental companies are the worst.
Recent posts in the travel blogosphere report of a hotel’s adding a mandatory daily parking fee for all guests—even those who don’t use a car or park there. Another hotel even adds a mandatory “valet fee” whether or not you use the service or even have a car. These fees are not chump change—up to $25 a day plus tax, in one case.