Really great movie except for one thing
I watched this for the first time today and thought it was really good. Very reminiscent of Fargo, but in a good way.
However, the appearance of the fake FBI agent really strains credibility. You're telling me the police station wouldn't have confirmed his identity instead of taking his word for it? Then again, the police force in this movie did seem rather incompetent regarding the investigations of the snowmobile accident and the shootout involving Lou, so maybe this was intentional on the filmmakers' part?
For this reason, Fargo is the superior movie. A Simple Plan is still really good though.