Thanks for the comments! I took 3 shots. The first one was at a faster shutter speed and the train was at a stop. The person was a bit too clear in the reflection.
As the train started to move I took 2 more shots, decreasing the aperture to get a slower shutter each time. Had to stop at 3 - the D700 shutter is very loud and I didn't want to freak her out.
There were only 3 or 4 people on the train.
I does look ghostly. The color version was a bit bland. B&W processing really changed this considerably.
Thanks again for the comments.