Continuity mistake: When Dylan confronts Norma with the earring of Emma's mother, he is holding it aloft in his right hand. Shots from Dylan's right rear and his hand is at waist level, the next shot from the front and it is held aloft again.
Revealing mistake: Norma is driving her car as landscape and cars traveling opposite her flash by. In her driver side mirror, there is no reflection of the cars passing by, the road, or any landscape. The mirror is blank.