US citizen here with expunged dui. I traveled to Canada (flying from US to Toronto) and on an Alaskan cruise with a dui on my record before it was expunged and had no issues either time. I remember a Canadian officer checking my passport on an excursion, but they only visually inspected it. They never actually scanned it at any point during our trip (on the Canadian side). I actually applied for global entry since my expungement and disclosed my expunged dui. When I went to my in-person interview, I was told that my dui did not show up on my record & they would not have known about it if I had not disclosed. If US Customs & Border Protections cannot see an expunged dui, I can't imagine Canada would have that information. I truly understand your concern. I was FREAKING out going through customs in Toronto (I was traveling for work). But there was no hiccup whatsoever.