Goofs

Two men appear behind Graeme and Clive in the diner when they receive the "Alien on Board" sticker. However, when the two hillbillies appear the two men are gone.

When Agent Zoil does a high-speed u-turn (handbrake turn) on the highway, the camera cuts to a close-up of him driving. You can see that he is driving on the right side of the car, instead of the left side.

When Graeme pulls over behind the sign and Ruth's father speeds by, there are almost no clouds, but when Haggard and O'Reilly speed by five seconds later, there are clouds.

When Paul is trying to push Agent Haggard off the road with the RV, Haggard has a small cut on his forehead. His car runs over some rough grass then back onto the highway, and the cut is suddenly twice the size.

When the RV hits the bird, there is a mark left on the windshield. The next shot shows the RV slowing down, and there is no mark on the windshield.

While riding for the first time in the RV, Paul states that the car accident was due to his not being able to reach the pedals, and that he therefore "needed to use the parking brake." The parking brake on the Crown Vic is a pedal located to the far left. There is no lever-operated parking brake.

When Haggard and O'Reilly are at the road block there are several Saguaro cactuses in the shot. They are suppose to be in Nevada, but the Saguaro cactus only grows in the Sonora desert, which would be central/southern Arizona into Mexico.

During the end credits, the two leads are still wearing the San Diego Comic-Con "Attendee" badges they had from their previous visit. They should be wearing Guest Badges now.

When Graeme and Clive are having lunch at Comic Con, we see Baskin-Robbins and Hot Dog On A Stick food vendors. Other than Starbucks and Mrs. Fields Cookies, the San Diego Convention Center does not let outside food vendors inside the building. They have their own café selling sandwiches, pizza and salad.

The state trooper's car says "Nevada State Police" on the side, and his uniform shoulder patch reads "State Police." Nevada has no state police. There is a state department of public safety, which has a highway patrol as one of its divisions.

One of the climactic scenes was when Paul tells his new friends why he is running & where he is going, but at that point in the movie he had already transferred his cumulative knowledge on to all of them so they should have known already. Although Paul is capable of transferring his knowledge to other people it could easily be possible that Paul may limit the knowledge he gives to others as to not give away all of his secrets such as why he is on Earth even to his friends as to protect them.

When trying to assault "The Big Guy" Clive breaks his sword. Later when they say farewell to Paul you can see the sword unbroken again on his back but Paul brings Graeme back to life and the aliens are shown healing the soldiers wounded by Zoil. With their powers and technology, fixing a broken sword for a friend would have certainly been child's play.

The normal eye of Kristen Wiig (Ruth Buggs) can be seen behind Ruth's blacked out glasses when Graeme and Ruth are arguing. Ruth's eye is meant to be deformed.

The ceiling of the actual Little A'Le'Inn in Rachel, Nevada, is covered with thumb-tacked dollar bills. The ceiling of the re-created set is bare.

When Clive strangles Paul and gets his fingers covered in some kind of mucus, after cutting back from the police cars to the characters, his fingers no longer have the mucus on them.

When the car Paul is driving spins out of control and flips, the roll cage is visible through the back window.

When Graeme is convincing Ruth to go with them and she says "Where would I sleep?", you can see her left pupil through the dark lens: it moves as she looks to her right twice and then back. In the next scene, it is shown that she doesn't have a visible pupil in her left eye.

When Graeme, Clive, Paul, and Ruth stop at Roy's Roadhouse, there is a table full of Navy servicemen in their white uniforms. There isn't a naval base anywhere in Wyoming, so there's no reasonable explanation for the sailors to be there.

When Haggard is chasing the RV with Zoil's car you can see the reflection of the camera vehicle in the RV's chromed front bumper.

In a night scene when the camera is looking through the front of the RV, a soft box rigged to the front right of the vehicle (as side/back light to the passenger seat) can be seen dipping in and out of frame, then finally completely into view.

The Velcro used to make the "Alien On Board" sticker easier to remove from the bumper is visible when Graeme rips it off after they find Paul.

When the black Crown Vic that appears to be chasing Graeme and Clive crashes, overtaking them, the roll cage installed in the car can be seen when it is back-lit by the illuminated dust.

When Haggard is chasing the RV with Zoli's car you can see the reflection of the camera vehicle in the RV's chromed front bumper.

There is no South Pass County in Wyoming. There is, however, a South Pass City in Fremont County.

The huge explosion that rips through Tara's house isn't very likely. She only left the stove on for a short while, and if there was really a massive concentration of gas as depicted by the explosion, the Agent who fired the shot that triggered it should have collapsed from inhaling so much gas.

When Graeme pulls over behind the sign and Ruth's father as well as Haggard and O'Reilly are right behind them, they should have seen them pull over.

U.S. Secret Service is specifically in charge of protecting the president, vice president and investigating counterfeit money. However, it's plausible for them to investigate aliens given the shady nature of the U.S. government.

Graeme and Clive are both British, yet Graeme uses the American pronunciation of the word "router" even though he used the British pronunciation of the word "schedule" only moments before.