Canada has always had the "open liquor" law. One debate that came along with hatchbacks was how to transport an open bottle without a trunk to put it in. (The key is "inaaccessible to the driver"). The consensus - never heard it tested - was that it had to be in the corner farthest from the driver. And yes, the passenger was also liable to be charged with an offense if they were the one holding the liquor. This was the law even when the lax attitude to drunk driving in the 60s was still the situation.
(A famous NB court case had the two guys parked in the car with the key in the ignition. The cop saw the driver had a bottle of beer, asked the non-drinking passenger to pass it to him, then charged the passenger too for handling the bottle. That went all the way to the supreme court to be overturned, IIRC. )
When I was growing up, 60s, I recall that people who did say drunk driving was bad would point to Sweden, where you could actually go to jail for 6 months (!! Horrors!) for being found drunk behind the wheel. "Not like North America where we don't seem to care..."
I remember talking to a much older guy from Switzerland who had moved to Canada, and he mentioned the european attitude to drunkedness in general was very different - more like it was pathetic, like someone who pissed their pants in public, rather that WC-Fields-hilarious. As a result, drunk was not some hijinks to be ignored.