I wonder if they see out the windows or even get in the door. Were you moving in the car or had you stopped. It seems just a little out of focus. Neat idea for a shot though.
Hey there :) I like your concept in this photograph, but I would suggest trying to get a more specific subject, ie. a cool ivy covered window or a larger view of the whole structure (top to bottom). For example, I personally really like the window in the front there -- it's covered by ivy but still catches reflection. Here's a link to an article from Kodak on how to better compose photos that's helped me -- [link]