Recreational and shopping trips to and from Canada are very common in Michigan; folks from Detroit cross over for entertainment, folks go across at Port Huron on their way to New York, folks come down to Traverse City for shopping, folks go to Stratford for Shakespeare. Canadian coins get spent as if they were US. "Canucks" is applied to Canadians, including immigrants, but I have never heard it uttered or taken as derogatory, but merely descriptive. Of course, there is so little difference between Ontario Canadians and Michiganians (especially yoopers) that prejoratives would be tantamount to pot/kettle/black.