I'd say Korea is the wrong place to start, if that's our strategy. Korea is a country that's a demonstrated export powerhouse. They have a complete imbalance already in automotive trade with Canada, and putting down the tariffs on both sides with no other strings attached is clearly going to hurt us more than it's going to help us.
If we want to use trade agreements to try to diversify our exports away from the U.S., it would be important to start with countries that don't have a strong auto industry, to begin with. For example, there are lots of countries in the Middle East that are significant importers of vehicles. We could negotiate more bilateral trade with those countries with less risk to our own industries. The fact that we're starting this strategy with Korea suggests we didn't think it through before we went down that road.