Hawn is Lou Jean Poplin, a petty criminal two weeks out of jail, who arrives at the "pre-release" minimum-security facility holding her dimwitted husband Clovis (William Atherton), another petty criminal who has four months left on his sentence. Lou Jean insists on breaking Clovis out of jail immediately, because the government has taken their two-year-old son away and put him in foster care.
Lou Jean sneaks Clovis past the guards, and they hitch a ride, meaning to get to Sugarland, Texas, where their boy is living. But after a patrolman, Officer Slide (Michael Sacks), pulls their driver over for driving unsafely, Lou Jean panics and steals the car. She crashes it, but when Slide finds them she steals his gun and kidnaps him. This leads to an extraordinary low-speed chase, as Clovis and Lou Jean take Slide at gunpoint across Texas to Sugarland, as a caravan of police cars follows, and citizens turn out at the roadside to cheer the fugitives on.
The Sugarland Express was Spielberg's first theatrical feature. Spielberg, 27 years old at the time, had been working in television since 1969, including the 1971 TV movie Duel. The Sugarland Express did poorly at the box office but didn't stop Spielberg from getting hired for his next project, Jaws. Sugarland is also notable for being the first film to use the Panaflex camera, a compact camera that allowed Spielberg to get complicated panning shots from inside a moving car. William Atherton later made a career out of playing obnoxious pricks in films like Die Hard and Ghostbusters.
The film is also noteworthy as the first collaboration of Spielberg and composer John Williams.
- Abusive Parents: Captain Tanner brings in Lou Jean's father and has him talk to her on the radio hoping that he'll convince her to surrender. Lou Jean and Clovis are away from the unit when he talks over the radio but Slide hears it all and it's clear that her father is (at the least) an emotionally abusive man.
- Artistic License – Gun Safety: Played straight with the reserve deputies, who prove themselves to not only have bad aim, but such poor trigger discipline that they shoot things that they don't mean to shoot. Clovis also shows poor gun handling. Averted with Captain Tanner, who makes sure a rifle is empty before using it to smash up the reserve deputies' car. Several other members of law enforcement show proper gun handling as well.
- Bittersweet Ending: Bordering on a Downer Ending, which is a rare instance in the Spielberg canon. Clovis dies, Lou Jean goes to prison, and they don't get their baby. But the closing title card says that Lou Jean got paroled after serving fifteen months and eventually reclaimed her son. Slide isn't hurt and continues working for the Texas Department of Safety.
- Bumper Sticker: The reserve deputies have four stickers affixed to the rear window and bumper of their car. One of them says "Register Communists Not Firearms", "Support your local police and keep them independent!", the peace sign with "Footprint of... the American Chicken" and "Honor it, Defend it" with the American flag. They foreshadow exactly what kind of delusional idiots the deputies are and the trouble they end up causing.
- Cool Car: Slide's 1973 Dodge Polara Pursuit Package cruiser. As are several other early 1970s Dodge and Ford police cruisers and several 1950s, 60s and 70s cars and trucks. Captain Tanner drives a 1972 unmarked Dodge Polara. Too bad quite a few cars get wrecked or shot up.
- A somewhat comical one, for the Bonnie and Clyde kind of "rogue couple" films. Q: What sort of couple would go out and thumb their noses at law and order and expect to get away with it? A: A couple without their heads on straight.
- A brief but serious one of vigilantes and why you don't want somebody with a gun running around taking the law into their own hands: it can cause a lot more harm than good. It ends up escalating a hostage situation—that Slide and Tanner were both de-escalating and had a good chance of resolving peacefully—to the point that Tanner has no choice but to use lethal force.
- Department of Child Disservices: Lou Jean's opinion, at least, as Child Welfare has taken her little boy away.
- Drive-In Theater: Lou Jean and Clovis are temporarily freed from the police caravan after another pair of cops try to ram their car as an Indy Ploy, only to wind up causing a wreck that blocks the caravan. They wind up taking refuge at a drive-in and watching a Road Runner vs. Coyote cartoon. Clovis, who is a little bit more in touch with reality than Lou Jean, identifies with the doomed coyote.
- Drives Like Crazy:
- Lou Jean closes her eyes while fleeing at high speed from Officer Slide. After she crashes the car, she isn't allowed to drive again.
- The reserve deputies end their shootout by driving around a used car lot shooting carelessly and crash into a dumpster.
- Driver Faces Passenger: The old guy that Lou Jean and Clovis hitch a ride from outside the prison thinks nothing of turning around and chatting with them from the driver's seat, as his car is going 25 mph on the open highway. This draws the attention of Officer Slide, starting the series of disasters.
- Empathy Doll Shot: At the climax, as they careen towards the border with the cops in hot pursuit while Clovis bleeds to death, Lou Jean loses it, and starts chucking all their stuff out the window. Among the things she throws out are a pair of shoes for the baby, and a teddy bear, which gets run over.
- Every Car Is a Pinto: One of the cars at the dealership goes up in a big explosion as Clovis and Lou Jean are engaged in a shootout with some reserve deputies.
- Funny Background Event: When the cops find the crashed car—Officer Slide had called for an ambulance before Lou Jean and Clovis kidnap him—two tow truckers are seen in the background, arguing over who gets to tow the car away. They continue to scuffle in the background as the police talk in the foreground, and the scene ends with one driver punching the other one out. This was unfortunately edited out of the original videocassette release.
- Intrepid Reporter: A reporter in a van drives up next to the couple for an interview while they're still moving. Captain Tanner shoots out their tires and causes them to crash into a ditch when they ignore his orders to clear out.
- Manic Pixie Dream Girl: Lou Jean, who sexes up Clovis in a men's restroom, badgers him into making a stupid escape from prison, and then leads him on a madcap adventure. It turns out badly for Clovis.
- Nice Job Breaking It, Hero: Or more accurately "nice job breaking it idiots".
- Early on, a Texas Sheriff and two Louisiana police officers tries to run the hijacked unit off the road. Without coordinating with anybody. All they manage to accomplish is crashing into each other and let the hijackers escape.
- Lou Jean's father is brought in to try and talk Lou Jean into surrendering. All he does is make Slide—who is the only one listening at the time—sympathize with her more.
- Later, the reserve deputies' shootout destroy what chance Captain Tanner has of a peaceful resolution to the hostage situation. They also end up foiling Slide's attempt at escape because they even end up shooting at him.
- Non-Indicative Name: Despite the word "Express" in the title, a word which would indicate trains, there are no trains in the movie.
- Outlaw Couple: Although Clovis and Lou Jean are really just petty crooks, and become an Outlaw Couple more or less by accident.
- Potty Dance: Lou Jean does this after saying she needs to pee, much to Clovis's irritation, as she passed up a bathroom at an earlier stop.
- Real-Person Cameo: Kenneth Crone, the officer who was kidnapped in the 1969 incident that inspired this film, appears as a deputy.
- Reasonable Authority Figure: Captain Tanner played by Ben Johnson. He talks to Clovis in a reasonable tone, and prevents the sharpshooting Texas rangers from taking a shot at the couple, even though they say there's a 90% chance of success, because he doesn't want to see anyone get hurt.
- A Simple Plan: Hitch a ride to Sugarland, snatch the baby, drive away. What could go wrong?
- Screw This, I'm Out of Here!: The kid that was riding along with the reserve deputies gets freaked out by their chaotic and insane shooting battle and runs away.
- Stockholm Syndrome: Officer Slide has clearly fallen victim to this by the time that he's trying to teach Clovis how to hotwire a car. At the climax, Slide sniffs out the trap that the cops have laid for Clovis and tells him not to go in, but Lou Jean insists that he go, and Clovis gets shot. It is downplayed in that Slide himself remains calm, does his best to keep them calm and keeps trying to talk them into surrendering peacefully. Building rapport with a hostage taker is exactly what you are supposed to do to deescalate a hostage situation. He also takes the opportunity to escape when it's presented to him.
- Toplessness from the Back: Lou Jean, as she undresses in the trailer that she and Clovis have broken into.
- Tranquil Fury: After the shootout by the reserve deputies, Captain Tanner is saddened that any chance of a peaceful resolution is gone. We then see that he is not the least bit happy with the reserve deputies' stupidity/interference and makes his displeasure very clear to them. He takes out his anger on the deputies' car, smashing the light bar, radio and its antenna, and has them arrested.
- Unwanted Assistance: While Captain Tanner tries to negotiate a non-violent end, a Texas County Sheriff and a pair of Louisiana police officers try to run the hijacked unit off the road. All they end up doing is crashing into themselves and gives the couple a chance to get away and hide. Afterward, Tanner makes absolutely sure that only the Texas Highway Patrol from a specific region are involved and orders everyone else to stay away. Unfortunately, that doesn't stop vigilantes from getting involved. After a vigilante shooting that only makes things worse, Tanner goes as far as to shoot out the tires of a vehicle that ignores his orders to stay away.
- Very Loosely Based on a True Story: The opening title card says the movie is based on a true event that happened in Texas in 1969, but much was changed. The wife didn't break the husband out of jail; he had been paroled two weeks earlier. They were not setting out to see their kid, but were just driving around when the officer tried to pull them over. They didn't kidnap the cop on the spur of the moment, but instead called for help with the idea of hijacking the police car. And while the story in the film unfolds over a couple of days, the real-life incident only took a few hours.
- Vigilante Man:
- The reserve deputies—who aren't actually reserves as they haven't been on any active lists for over a year—think they're legitimate law enforcement. They are actually complete idiots. They escalate an already dangerous hostage situation, they shoot without regard for anyone's safety (including their own), damage and destroy property (including their own), and traumatize a poor kid (who is the son of one of the deputies) who does the only smart thing and gets out of dodge. Tanner tries to escape in the confusion but the attempt fails because they even shoot at him. The captain rightly rips into them and has them arrested for their idiocy.
- It's clear that there are many others besides the reserve deputies that are looking to take matters into their own hands. While they're driving through the street of a small town, several police officers are seen searching and disarming several people. It leaves a fairly sizable pile of guns.
- Wounded Gazelle Gambit: Lou Jean pretends to be hurt worse than she really is after she wrecks the car so that Officer Slide will have to carry her out of the car, so she can get his gun.