I was in San Francisco in December and used a car service called Uber. It uses a phone App to bring a driver to you quickly and is cheaper and frankly nicer and cleaner than a taxi. I have used it a little here in DFW, and I am thinking about using it to go to incall appointments and spas.
I know years ago some religious nuts would post your license plate picture if they saw you at certain SOBS. The Uber could cut down on that.
Also, providers could use it for outcalls and not have to worry about the client knowing her car.
I know there will be some who blast this idea, but it might work for some. Just a thought.