Continuity mistake: At the end of the scene where Frank chases the car on a bike, he jumps into the car through the driver's window. You can see broken glass flying, but in the very next shot the driver's window is intact again.
Continuity mistake: In the opening birdseye shot of Frank waking up on the gurney, the explosive bracelet that sets the plot in motion is missing, but after a quick zoom, it appears on his wrist.
Continuity mistake: When Frank is chasing his car on the BMX bike the number and arrangement of pegs on the bike changes with each shot.
Continuity mistake: At the landscape, where Frank should do the striptease to get his keys back, you can see, that the distance of the phone book on the ground and the Audi both change several times, from shot to shot.
Continuity mistake: Just before the two-wheel stunt between the trucks, the ramp to take him up on two wheels is visible.
Other mistake: Near the end when the bad guy blows up in the train, the fireball created by the exploding bracelet would be much more suitable to several kilos of high explosive or a fuel explosion. It could never have been created by the amount of explosives stored in a bracelet (see as well Mythbusters, the James Bond episode with the exploding pen).
Factual error: When Frank's Audi plunges into the deep body of water underneath the bridge, he succeeds in using the air from the tires to fill some empty bags in the trunk with air in order to send the car back up to the surface. In reality, the air in the tires would not be enough to keep it afloat, no matter where it's stored. The air in the tires will expand by a factor of something like 33, but that's still not a large enough volume of air to refloat the car.
Other mistake: Franks Audi smashes through the steel barrier on the bridge. Whilst we can accept the bodywork is toughened up and is bulletproof, its a plastic front bumper, plastic grille, glass/plastic headlights, yet there isn't even a scratch on either of these items after the car is seen driving after its pulled from the river after smashing through said STEEL barrier. The barrier would be particularly strengthened to attempt to prevent such a maneuver that Frank performed.
Plot hole: In the large chase scene, Frank hits the shoulder at 140kph (~85mph) but the car doesn't shake, slide, or act in any way like it should. Later, when he's moving around 220kph (~135mph), he somehow manages to end up on two wheels. To top it all of when he ends up between the semis he appears to be moving just barely faster than them which would mean he had to slow down somewhere. When his wheels make contact with the one semi the car doesn't jump or skip as expected because it's not moving very fast compared to the semi. I know this scene is for effect, but they could at least attempt to make it somewhat based on real physics.