Revealing mistake: When the police car crashes through the grating that was dropped down in front of it at the end of the tunnel, the occupants are dummies - they just bounce about in the same upright position whilst the car drives into the river.
Factual error: While Bridger is watching the film of the Mafia boss following Beckerman he signals for the film to be stopped so he can look at the close up shot of the man. He is watching a 16mm film shown through a bog standard projector - stop a film like that for more than two seconds without closing down the projector shutter (this doesn't happen - if it did the screen would darken instantly) and it will melt and catch fire. This doesn't happen.
Plot hole: Why on earth do they drive the Minis up the ramps into the bus while it is moving? They are on a long, straight, relatively quiet stretch of road, but there are cars and buildings about. That ramp is going to make a noise like the sky coming down (we see sparks as it scrapes on the road) and they put on a display anyone would be, frankly, amazed to see. Don't they think one single person would call the police? Don't they think that reports of three brightly coloured Minis will be connected with the recent robbery? They cannot possibly think they have to load the Minis on the run in order to elude the police; they have lost the police cars and are no longer being pursued. Why not just park the bus on the hard shoulder and drive the Minis sedately up that ramp? An unusual sight, maybe, but nowhere near as clumsy, obvious and attention-getting as the way they do it. They are asking to be pulled over and arrested.
Continuity mistake: When the car transporter is trying to break into the building, where they are transferring the gold from the security vehicle, a car drops from the transporter, lands on a police car, and the blue cover from the police light comes off completely in the first shot. But a second later you see the face of the policeman with the light in the foreground, which now has a jagged broken base left on the car.
Visible crew/equipment: As the armoured truck is midway from the airport to the Fiat plant, the film crew is seen in the mirrored finish of the stripe running down the length of the truck.
Revealing mistake: When the three Mini Coopers drive onto the coach, the first Mini doesn't have fitted headlights. It also has a brand new rear wheel fitted that is clean and the rest are dirty.
Continuity mistake: After the gang is pulled off the bank job, they race away in the three Minis - as they go through a tunnel at one point they roll up and down the sides of the tunnel. The mistake is that each car supposedly has two occupants, but on one shot of the cars in the tunnel, one car has only a single occupant - visible because the car following has his headlights on illuminating the car in front.
Continuity mistake: When the 3 Minis are pushed off the coach, if you look carefully there is view shown briefly of the cars interior, which has red door pillars. When the shot reverts to the external view the cars colour is white.
Continuity mistake: Right at the beginning, the red Lamborghini goes into the tunnel and is blown up, yet when it is taken out not one part of the bodywork is charred, it is still a shiny red.
Continuity mistake: Each of the Mini Coopers were fitted with three spot lamps on the front grille/bonnet in a triangle formation. In part of the chase sequence through the sewer, two of the Minis have sprouted three more lights - one under each headlamp and one in the centre of the grille under the three original spot lights.
Continuity mistake: When the Minis are going through the tunnel, the police car behind them has a set of lights which are the same as the Minis, which it did not have before.
Visible crew/equipment: When the three Mini Coopers come out of the sewer and drive towards the coach, you can see 2 people in the coach. "Big William" and Mr. Toms who really drove the coach.
Other mistake: When the Mafia are having a dinner party, the film cuts to Charlie Croker throwing his bicycle into the substation to cause a powercut. After the big explosion, the camera switches back to the dinner party and then all the lights go out. But before the lights go out, if you look at the end of the dinner table, there is a doorway, and you can see smoke coming from the candles which have already been lit before the lights go out. Within seconds of the power cut, these candles are brought in from doorway and another set comes in from the left-hand side. A little premature.
Continuity mistake: When Charlie Croker breaks into the prison and meets up with Mr. Bridger in the loo, just before they leave, the toilet chain is pulled. It was already swinging.
Factual error: When the cars are in the garage being prepared for Italy, Freddie tells Charlie that the red Mini Cooper is having its differential worked on. The mechanic has jacked up the rear off the car and is working on the back axle, but Mini Coopers are front wheel drive. The differential is on the front axle on these cars and working on it would mean removing the whole engine/gearbox unit.
Other mistake: When the film about planning the job is being shown to Mr. Bridger in the prison: at the end of the film the mafia man walks right up to the camera to watch the English guy walk off. This seems a bit odd, him being able to walk right up to the camera and the camera operator still filming. Wouldn't he have wanted to keep the fact that he was watching them all the time a secret and not give the game away that the mafia were on to them?
Continuity mistake: The Minis at the end are pushed out of the bus with no rear windows, the Aston pushed over the cliff becomes a Lancia at the last moment, and the Lamborgini pushed over the cliff is so toy-like - it doesn't even have an engine... [Regarding the Lancia, the comment is correct. However, it was a deliberate substitution. The Aston went over the cliff and spontaneously burst into flame almost immediately. The director felt that it looked too fake and the Lancia was substituted to make the stunt longer and more realistic.]
Continuity mistake: When we see the computer tape on the tape drive just before it gets to the altered data and messes up the traffic light sequence, the tape is visibly twisted. In the next shot a few seconds later, it is straight again.
Revealing mistake: After stealing the Bullion the gang make off through a shopping mall. As the scene changes to show the Minis descending a staircase it can be seen that the door of the front Mini is wide open and the passenger is getting in as the car moves off. It shows that the car was stationary before the start of the shot and not actually descending the stair.