There are cars where the security is trivial to bypass. Create a list of those make/models.
1) Raise insurance premium on those models.
2) Force dealers that every time they sell such a car, they must get a signature from the buyer on a piece of paper that says "I recognize that the security of this car is borderline non existent and I will be paying a lot more in insurance because my car is trivial to steal".
Grandfather in people who already have such make models or give some time to manufacturers to improve security.
I don't think that'd even be an issue. A manufacturer wouldn't be allowed to offer insurance directly to customers in Canada. At least in BC there are mandatory insurance through ICBC.
So if the intent of the government is to increase security, make those cars less appealing by making them more expensive.
Grandfather in people who already have such make models or give some time to manufacturers to improve security.