Some years ago, I made a flying run out of the bus station in Boston, to grab a cab to take me to Cambridge. In a hell of a hurry, I spied a yellow car with a black driver. I should have realized that cabbies dont drive Volvos with sun roofs, but, I stuck my head into the sun roof and asked if she was free!! I cant describe the look I got as she informed me that she was not a cab. I'll bet she either traded cars, or she had that one painted.