Automated Automobiles: A black car, and later the General Lee, are turned into these via remote control.
Even Evil Has Standards: Boss gleefully masterminds a plan with his three associates to crash the General Lee (via remote control) into the train hauling a multi-million dollar gold shipment ... until the cronies capture Bo and Luke, and plan to kill them after the train job. Boss immediately regrets his actions and helps Jesse find the boys, who by the time they show up have already taken out the train robbers and gotten the General Lee back.
Fleeting Passionate Hobby: Boss really gets into the model train he's using to plan the Train Job, wearing an engineer's hat and blowing a train whistle.
Watching this little train go around this little track is the most fun I've ever had!
I Will Only Slow You Down: Daisy twists her ankle while running from the remote-controlled General Lee. Bo stays with her while Luke runs to off to stop the men with the remote control.
Instant Expert: When Luke gets his hands on the remote control somehow he knows exactly which levers to turn in order to make the General Lee jump over the train instead of running into it. He also makes the horn honk the familiar "Dixie."
Leave No Witnesses: The three train robbers plan to do this. Problem: Bo and Luke Duke are the witnesses in question.
Literary Allusion Title: The episode title is an allusion to Agatha Christie's Murder on the Orient Express, though apart from there being a train called the "X Express" involved it has no connection to the plot.
Racing the Train: Early in the episode Bo driving the General Lee tries to cross the railroad tracks before a very long freight train blocks their path. He doesn't make it due to almost running into the black car doing a test run of Boss's plan to crash into a train carrying bullion.
Railroad Tracks of Doom: What the crooks hope to accomplish by piloting a remote-controlled car crashing into a train.
Shout-Out: The Dukes get stranded because the bad guys steal the General Lee; they walk down the road and find a phone booth to call Uncle Jesse at a place called "Waylon Corners."
Waylon Jennings: I don't know what's down there, but I do hope it's deep and wet. Or at least nice and soft.
Train Job: Boss plans to use a remote controlled car to derail a train carrying $2 million in bullion to Atlanta, stealing the gold, silver and platinum.
