Why do Car Rental Companies Charge for a Second Driver?
One possibility is that it's price discrimination, that they think that if two people are going to use the car, the customer expects to use it more and so will pay a higher price--but given how competitive the market is, that doesn't seem very plausible. Another is that it's an attempt to mislead customers doing price comparisons--put in additional charges that won't show up when you go to a web page to compare prices from alternative sellers. That doesn't strike me as terribly plausible either.
Does anyone have a better idea?