Corrected entry: Throughout the films, the time jump occurs at the end of the flaming skid marks. But, when Marty crosses the bridge near the end, the flames go right across the incomplete section even though the DeLorian has already gone at the start of them.
Gary O'Reilly
28th Sep 2007
Correction: This is just wrong. For a start, the very first time jump we see in the first film ends up with Marty and the Doc slap bang in the middle of them. If the car disappeared at the very end of them, they'd have been run over. See: http://www.hhcc.com/wp-content/uploads/2006/04/Back_to_the_Future.jpg.
Gary O'Reilly