US auto manufacturers need to relocate their Canadian factories back to the USA. A 25% tariff on Canadian made vehicles should be sufficient incentive to do just that.
One item needing to be mentioned is that a lot of those plants up here produce vehicles that are already marginal in the modern marketplace, like US badged sedans (which with a few exceptions sell about as well as free venerial disease). Some of them are slated to be canceled without replacement. So it might not be a matter of moving plants (which could eventually be moved back) but just shuttering them. Bit of a difference.
Er, “plants up here” should be “plants up there (in Canada)”. I live in Texas, not the Far Frozen North.