Continuity mistake: The tyres on the crotch rocket motorcycles they were riding kept changing from knobbly tyres to road slicks, back and forth depending on what terrain they were on. Easiest to see when Ethan skids on the road to avoid the white van - clear shot of slick tyres - then about 30 seconds later they're on the dirt, he skids into the old car and you can easily see that he's got off-road tyres front and back.
Continuity mistake: In the car chase scene with Nyah after they split and hit again and are spinning look at Ethan's car. The driver's side in the close ups was on the American side, then in the spin it is reversed to an English side. (It is a negative image - the license plate is reversed). The next image is back to normal.
Revealing mistake: When Ethan's pal is in the helicopter and Ethan is escaping on the motorbike he fires a grenade launcher at the car - he misses the first time, gets the car the second time, but you can clearly see the bridge is made of wood - where the car gets blown up there's a big concrete/steel plate to support the bridge. (01:38:30)
Continuity mistake: When Ethan finishes showing Nyah the pictures of the aeroplane crash so she can see what kind of man Ambrose is, she puts out a candle with her hand. Then when they show her from the front, it's lit again, from the side it's out, then lit from the front, AGAIN!
Continuity mistake: In the scene where Nyah is walking up towards Ambrose's house, the wind is playing havoc with Nyah's hair and scarf. Throughout the scene, there are several shots of her where there is no wind, her hair is not moving and the scarf is perfectly placed (most noticeably when she steps off the boat onto the walkway).
Continuity mistake: In the first car chase, in the clip right after Nyah says '. you gotta catch me', you see the double yellow lines on the road. But in previous clips, and on the clip right after, the lines on the road are white. The clip with yellow lines are from another stretch of road.
Continuity mistake: Near the start of the car chase at the end, a white car loses a hub cap in extreme close-up, but when it wipes out completely and flips over a few seconds later all its hub caps are still on.