Revealing mistake: The roller coaster used for the Devil's Flight is really the Corkscrew at Playland in Vancouver, where all three movies were filmed. If you look during the opening credits, you can see the name "Corkscrew" up in the lights above the coaster. After this, it says Devil's Flight during the rest of the roller coaster scenes.
Revealing mistake: At the end of the film where Wendy is stuck on the track, she looks back at everybody that died. At the right side of the screen, right in front of the camera, you can see a dead girl blink.
Chosen answer: They would've died, but Death "knew" they wouldn't have stayed in the car. If they had stayed, Death would change his death.