Every time you hear a train whistle through the movie, it sounds like it's from a steam engine. Steam locomotives where completely retired on class 1 railroads by 1959 thus making it impossible to hear a steam whistle blowing in 2003.
In the opening scenes as she is driving away from her job as a cleaning lady, she is shown from the front driving the car, she isn't wearing a hat. The cut to a shot of her seen from the rear of the car and she has a hat on. They go back to a front shot and the hat is once again missing.