When Mia is treating Dom's gunshot wound, she says the bullet is not inside, which means there has to be an exit wound. However, Dom hasn't one.
In the beginning scene after Dom asks Letty to jump, you can see that the truck driver jumps from the driver side to the side of the road. In the very next shot, the truck is on its correct lane, so it wouldn't be possible for the driver to jump that far.
During the race for a spot as one of Braga's drivers, the GPS says that Don and O'Conner have a quarter of a mile until their destination. It takes them 48 seconds to finish the quarter mile.
The second Tunnel Race, Dom jumps to other car and his own car blows up,
then at the prison bus scene, O'Connor rides "The" car in the exactly same condition (the rosary still hanging on the mirror).
When Brian is driving up to the prison bus, the air scoops on his car go from 3 scoops to 1 scoop in the next shot, then back to 3 scoops.
In the beginning they unhook the gas trailers and reconnect them to a tow truck. Simply unhooking a tractor trailer and dragging it away would not work as the air line needs to be connected for the brakes to release.
During the first helicopter scene, the pilot calls over the radio that he is "At angels 5." This means he is at 5000 feet altitude. The scene reflects a much lower altitude. They probably meant "cherubs" 5. Angels are big numbers (1000's) while cherubs, small angels, are small numbers (hundreds). Angels and cherubs are military pilot slang.
When O'Connor is going after the criminal, the criminal is shooting with a six chamber revolver. However, when he takes the firsts shots at Brian he fires 3 bullets. When Brian pushes him off of the building he fires another 4 bullets. That's 7 bullets in a six chamber gun.
Agent Penning says with regard to Arturo Braga that "he's moved more heroin across the border than Escobar did in 10 years." This references the notorious Colombian drug cartel leader Pablo Escobar, who rose to power in the 1980s. However, Escobar and his Medellin cartel primarily trafficked in cocaine, not heroin as Penning's quote would imply.
David Park's car is described as a '98 Nissan 240 with illegal mods', which would make it an "s14". Though it is actually a Nissan Silvia S15. S15's were never produced for North America, while S14s were, which would mean it was imported from Japan. The body lines on the rear quarter panels, front end (headlights, fenders, etc.), and taillights prove it's an S15. It's also right-hand drive.
Dom blows up four cars by pushing the cigarette lighter in and releasing nitrous oxide into the car. Nitrous oxide is not flammable or explosive at room temperature, however, just because it's a NOS tank doesn't mean it actually contains nitrous oxide. It's likely that Dom had planned beforehand and filled the tank with a flammable gas.
During the end credits a car's engine is shown firing in cutaway. The graphic indicates a combustion event on every stroke of the piston. While not common some cars with custom engine management systems run 'wasted spark' firing. In this system there is a spark every compression of the piston.
Dominic's Chevelle has narrow wheels while in the race to make Braga's team. It may be more difficult for him take the corners with drag front wheels but not impossible even though the car was set up for a straight line, and not cornering.
When Brian is under a bridge, talking on the phone with agent Penning after the hijacking of the Hummer with 60 million dollars-worth of heroin, it is dark. When he heads to the back of the Hummer to see where has Dom gone, it is sunny.
Toward the end of the chase scene where Brian's Subaru Impreza STI is rolled over, you can clearly see that the fuel tank, prop-shaft and exhaust have been removed for the stunt.
Fast & Furious (2009) takes place 5 years after The Fast and the Furious (2001). Assuming the first took place in the same time period it was made (2001), then this installment would take place circa 2006. Brian driving a 2009 Subaru STI is therefore impossible.
When Brian is choosing cars out of the impound lot, he is seen choosing several Nissan GT-R chassis for rebuilding into a car to be used in the street race to work with Baraga. One of the cars chosen is an R35 GTR. As the movie takes place 5 years after The Fast and the Furious (2001), this would be impossible, as the first GTR was not seen on US soil until 2008, two full years after the movie takes place. This continues into Fast Five (2011) - there is a GTR featured in that movie as well, however, The Fast and the Furious: Tokyo Drift (2006) takes place in approximately 2006, which is also after the events in both Fast & Furious (2009) and Fast Five.
Brian drives a 2009 Subaru STI, however, this movie takes place before Tokyo Drift which was in 2006.
The yellow BMW M5 shown in the race has the distinct sound of a BMW inline 6 engine. The M5 had a 5 litre V8 engine, which sounds different.
Torreto's Buick Grand National has the unmistakable sound of a V8 when in fact all GNs had a turbo V6. Obviously a V8 could have been transplanted but then why go to all the trouble to make this car cosmetically correct as a Grand National (right down to the Grand National logo on the front license plate)?
The blast of the cannon that rolls the tanker semi is clearly visible.
When Brian steals the Humvee, and stops for Dom to get it, there is a camera very prominently reflected in it.
Before O'Conner breaks through the window at the end of the roof chase, camera and operator are visible in a window during the pan shot.
After Brian transfers Mia in the FBI building, there is a shot of a red car with chrome bumpers. In the bumper you can see a cameraman walking forwards with the camera.
Han does the handbrake turning right and a camera car is reflected in the chrome bumper.
When Dom is at Brian's side in the desert near the end of the movie, they are in a vast, flat desert. When the camera pans out to show the police cars driving towards the two, the scenery dramatically changes, and resembles a Coastal Plain with grass on the ground.
As the movies switches locations to Panama City, Panama (15 minute point) they actually show Guatemala. The scene starts looking at Volcan De Agua and pans down to a very famous cross (Cerro de la Cruz or Hill of the Cross) overlooking Antigua Guatemala. It is not Panama City, Panama.
Why did they not know who Braga was and what he looked like when they clearly had his photo on Government records when it was faxed over and showed his correct name etc.
Brian's checkered past as a convicted criminal boosting cars would make him ineligible to work as a member of the FBI.
Earlier in the day Brian learns that Dwight had made it into Braga's team by winning "previous races", yet when he meets Dom later (after Dom won the race to get into the team) he says "It's too bad about Dwight, getting your house raided by the fed's the same day you make the team". Assuming Brian learned about Dwight making the team early in the day, had time to completely build a custom car, and compete in Braga's final race, Dwight still couldn't have won a spot on the team the "same day" he got his house raided.