At the end when Bill flips his car trying to avoid the Firebug's flames, the car that actually flips is a totally different car . Bill's car has four square headlights but, the car that flips has two round headlights.
The hand lettered sign for Cameron Auto Sales is misspelled "Cameon".
When Ralph is flying to help Tony, who is being pursued by plainclothes cops, he lands inside of an open manhole. When Ralph emerges from another manhole , it is apparent that it is a stunt double in a blond wig .
When Ralph is having the vision of Cameron talking to his employee, Cameron's lips don't move with his words.
As Bill is driving down the street toward the firebug, there are two persons (most likely crew members) standing next to the pick up truck on the right. They too disappear when the camera angle changes.