Before Richie leaves L.A he talks about flying to Maine and several times after he arrives, when he gets spooked, he talks about getting on a plane and going home but his car clearly has California license plates visible in several scenes (when he stops in front of the old theater, when the group is getting their stuff together to go back into the sewers). The car was supposed to be a rental and should have had Maine plates (or at least a New England state!)