The one shown in 2013 was different than the one shown in early 2012. It had side mirrors instead of cameras and a slightly different interior, and was supposed to be closer to the final design than the original prototype. This is the white one that has been featured at various events an on TV since then. Of course, it's expected now that the production model has evolved significantly from even that design, so who knows how much of it will carry over.
I will be very disappointed if the Model X is not at NAIAS. Not only because I am looking forward to seeing it up close, but because until the beta makes a public debut it makes you question whether Tesla can meet even their revised Q3 first delivery schedule. You can't do all your testing indoors or at night, so it has to show up on the road sometime if they are really making progress on proving the design.