When Jeff is driving up to Happy Lee's place, he drives past 1 VW Beetle and then pulls up beside another one. In the next shot, his car is seen parked away from it and that 2nd VW Beetle is positioned a little further back.
As Jeff walks up to Happy Lee's house, the front door is blue, when Happy Lee answers the door, the outer part is white.
Despite being a ghost, Marty reflects a shadow.
Toward the end, Jeff is pursued by a Ford Cortina, reg OYR 877F, which crashes with a loud sound effect into a stainless steel lamppost. When you see the aftermath of this crash the bonnet (hood) has 'popped' up and there is smoke/steam coming from the engine. However the front of the car appears to be in an immaculate condition and the same applies to the lamppost.