Andrew sent me a link for railroad inspection cars, and there were a some I haven't seen before! Thanks Andrew!

1929 Packard seven-passenger limousine and the 1938 Buick Special

a 1938 MacLaughlin Buick limousine

a new “Rail Truck” made by Coordinated Transportation Inc. of Minneapolis, Oct 1937, I would have guessed there would be more on the internet about this COE streamliner, even the rear wheels seem to have moon discs

http://discussions.mnhs.org/collections/2014/02/rail-truck/
http://www.trainweb.org/oldtimetrains/photos/inspection/gallery.htm