Standards of cleanliness? In what city? I would never wear white in a cab. A lot of cab drivers also stink almost as bad as your average pan-handler.
When I was in grad school, I drove a taxi. This is a pretty long time ago, but let me tell you, y'all passengers don't always smell so great, either. I remember an August day when a guy got in my cab at O'Hare just drenched in Calvin Klein cologne (which was a fad at the time and smelled like a skunk in a whorehouse). I had to drive him all the way downtown, with my eyes watering and me choking. I had the AC on full because it was hot and finally by about Belmont I just said, "fuck it" and opened my window, wanting to stick my head out like a labrador retriever. This is before they forced cabs to have the plastic barrier between the driver and passenger.
The worst part is he gave me a two dollar tip. Another Gordon Gecko yuppie throwing nickels around like they were manhole covers.