Chatterbox: Down to Earth

I have a problem. I am horrible at making decisions so I'm asking you guys. 

 Me and my dad were going to my glasses place (I had run into someone and the nosepads got bent) when we saw 3 50s-ish cars.

 In one of the cars, was a family of 4. 2 parents and 2 little kids of about 5 and 6. Anyways, I saw that the dad had a cigarette, then I also saw the mom had one, in her mouth. (The light was red)

 The car didn't have a roof, it was like a 50s convertible, but I still don't know if smoking in a car while children are in there is allowed. Especially since a law was passed here in Canada that you can't do so.

 So what do I do? (And if you suggest telling the police, I forgot the car's license plate number)