In a car chase Anthony Wong's Lo is driving Nissan Cefiro. But in the end of the chase and after that it turns to be Audi A4.
At the end when the Audi police car hits the Nissan Skyline, the Audi becomes a Nissan and the Skyline becomes a Toyota Corolla Levin BZ-G.
Cheung's Nissan Silvia changes throughout the movie. The sunroof disappears as do the vents on the hood.
The clock on Cheung's Nissan Silvia changes throughout the movie- when he is practicing doing "the turn", the clock jumps about 8 minutes in two different shots. When he is on the highway, it is 4:07 and the clock suddenly changed in the next shot to 12:26.
During the mountain chase, Lo's Nissan Cefiro has a blue light on the passenger side, in the next shot this has changed to the driver's side.
At 1:04:12 to about 1:04:22, a desk-bound policeman or clerk in the foreground is seen reading and flipping through a book which has empty pages.
At the end of the film, Cheung tells the doctor that she will never make it to the hospital in this traffic. However, the road is completely empty.
Cheung chased Jiang on his own through the tight L-shaped passageway, requiring the latter to pull a 90 degree semi-doughnut in order to escape. Cheung could've called his colleagues for reinforcement and blocked the passageway, therefore the chase (and the rest of the movie) would've been over.
Any driver know that you do not escape through narrow passageway in cars.
Any driver know that you do not escape through narrow passageway in cars.