Steve,
Using AG4 v. 4.2.5, when I try to view the "last car" before I decide to use it in a new consist, the image which Shape VIewer brings up is just the display track. No rolling stock is displayed, no matter what I choose. The viewer for "change locos" works perfectly fine.
I'm surprised that no one else has reported this. So maybe I have something wrong with my set up, and it works for everyone else???
Norman