"Bona fide occupational qualifications generally only apply to instances in which the BFOQ is considered reasonably necessary to the normal operation of a particular business. For example, a Catholic college may lawfully require such positions as president, chaplain, and teaching faculty to be Catholics, but membership in the Catholic Church would generally not be considered a BFOQ for occupations such as secretarial and janitorial positions.

Mere customer satisfaction, or lack thereof, is not enough to justify a BFOQ defense, as noted in the cases Diaz v. Pan Am. World Airways, Inc.[6] and Wilson v. Southwest Airlines Co..[7] Therefore, customer preference for females does not make femininity a BFOQ for the occupation of flight attendant.[8] However, there may be cases in which customer preference is a BFOQ—for example, femininity is reasonably necessary for Playboy Bunnies.[9] Customer preference can "'be taken into account only when it is based on the company's inability to perform the primary function or service it offers,' that is, where sex or sex appeal is itself the dominant service provided."[10]"

My guess would be that excludes gender discriminating people driving cars outright. While obviously, as discussed in the article, women may prefer women drivers, the driver being a woman is not functionally necessary to drive a car.

This is why Hooters doesn't have to employ men as servers. http://www.businessinsider.com/how-can-hooters-hire-only-wom...