These Train Days seem dependent on local sponsors. If somebody in Texas wants the exhibit train, organize a Train Day event.
A Train Day even doesn't really need a sponsor. A table set up with Amtrak timetables, Brochures, Amtrak Vacatins brochures or any Amtrak material to give to people boarding the train can cause some buzz. Call your local newspaper to come take a picture. If your station is manned, see if a reporter will interview the employee for comments. If you have a Rail Fan group, get their participation. See if a government official is a supporter of passenger rail and get them involved. This isn't rocket science! I am sure Amtrak can give you some guidance and assistance with promotional material. It is all well and good for rail fans to say they support passenger rail, but this is a chance to really do something.....however small it may be!