The geography of the drive from South Bend to Detroit to Canada is very flat and rural. The film shows huge mountains, lakes, and forests, none of which are present in northern Indiana and southern Michigan, which are about as flat as any place can be, and full of farms. Also, southern Ontario looks nothing like Big Bear, where the cabin scenes were filmed.
Indiana license plates are numbered by county. While the movie takes place in St. Joseph county (as indicated by patches on the sheriff's uniform), neither Lucia's nor Bill's plates match that county (or any neighboring ones).
When Lucia (Lisa Kudrow) is following Jason and Martin into Canada, her map shows they are crossing at Windsor Ontario, but the next scene shows the border crossing in a rural setting. The crossing at Windsor is a 24 lane bridge crossing.