Skip ahead to the Freeway chase scene. Go to the part where the agent jumps on the car, and the car collapses. Pause it right when the agent switches cars, and the screen does a side shot of the destroyed car upside-down in slow motion. You can see all of the hydraulics and mechanics in the seat, and also that there is no driver. If you watch the making of the film, it shows that they used hydraulics to make the car crunch up and flip, and they used remote-control technology to keep stunt men out of danger.