When Derby pulls into the post office, he pulls in directly beside the pickup, with the yellow newspaper box near the right fender of the car. When he stops, there is a space between his car and the pickup and the newspaper box is to the left of his car.
Cassandra is practicing her routine in the garage, Stan shows up, tells her to continue, then he talks to Dwayne; a couple minutes later, Stan leaves, and Dwayne shuts the garage to leave. Where did Cassandra go?
The main plot point of the movie is that the USPS will give an award of $100,000 for evidence of a murder of a mail carrier. This is incorrect. The USPS will only give that award for information that leads to the arrest and conviction of the murderer (or assailant) of a mail carrier.
If you look at Darby's license plate it begins with "64" but Montana license plates begin with the number assigned to the country. There's only 56 counties so there isn't any that begin with 64, and as Cut Bank in in Glacier County, it's number is 38.