Welcome to America, via the car and the internet.
Sounds like you will have a very unique car, whether there or were it here (in European dress).
You may have different mirrors on the doors, side marker lights between the front wheels and the front doors, 9004 or9007 dual-filament headlights (meaning one light bulb covering more space in the headlight capsule, a different blinker area in the main headlamp capsule, a different rear bumper cover to accomadate the European license plate. That'* all I can think of off-hand.
Inside I believe the only difference will be the instrument cluster will be the same as a Canadian Bonneville would have here in North America. AKA -reading KPH in the large #'* and MPH in the smaller #'* as well as coolant in C, and boost guage will read something else too. Oh, the digital climate control will have the option for C* and F*, but that was standard on all SSE/SSEi'*, regardless of their destination when built.