The times when Trevor is with the waitress
So we learn that in Trevor's mind he is talking and interacting with the waitress and her son, who happen to be the mother and her son who he ran over. I'm wondering how that fits in with him at the fair and at her house. Was that all imagined up, or was he actually at those locations for real and either was with someone who he imagined to be that mother and son, or on his own and imagined them there, similar to in Fight Club with the Narrator? Ivan was also imagined up as a physical representation of his guilty conscience but he seemed to be in real locations when he interacted with him.
If all those locations were real then whose house was he in when he was drinking wine? Definitely didn't seem like he was close enough to the actual waitress at the airport to be her place.