The crew's Cadillac is frequently seen with a Michigan front license plate. Michigan only uses a single rear license plate.
When Sunny is pointing the flintlock pistol at Crunch it is not ready to fire because the Frizzen should be in the down position to hold the priming gunpowder.
In the beginning of the movie action in set in Warsaw but what we see is obviously Budapest with Danube and famous Chain Bridge (Széchenyi lánchíd).
The road signs mentioned are in fact Canadian, on Highway 401 leading out of Windsor, Ontario.
The Romanian flag is visible in many shots at the beginning of the movie. Moreover at min 26.29 the Romanian Palace of Parliament is clearly visible.
The motorcycle chase in the subway train was recorded most likely in Romania. Warsaw metro looks very different, also all the signs are visible are either in English or Romanian.
In the nocturnal aerial shot of Niagara Falls the river is glowing in the wrong direction. The Canadian city shown is in the left bank of the river, not on the right back, as shown.
The officers chasing with motorcycles in Poland wear Italian Carabinieri uniform.