The Machinist (2004)

Revealing mistake: After Trevor is hit by the VW Bug, the arm he lands on disappears partially into the street, making the CGI obvious.

Ivan: Oh, no. You look like you seen a ghost.
Trevor Reznik: Funny you should say that. The guys at work don't think you exist.
Ivan: That's why I can't get a raise.

Trivia: When Trevor is following Ivan through the tunnel, he reads the number plate out as 743 CRN on the red Firebird. When the shot changes to Trevor's pickup, the number plate reads NRC 347. Could this be a clue to a mirror image twist?