Canada

Australia had automotive production. They don't anymore, because it wasn't viable.

South Korea is definitely an exporter of automobiles. Thing is it took them about ~40 years to get to the point where they caught traction with it. The early Korean exports were pretty low quality and sort of unreliable (different people had different experiences). It took time for their R&D to work it out, and for economies of scale to develop.

It's not the belief that we need to sell to the United States that would be stopping us here. It's that they are right next door + 100 years ahead of us on R&D and progress, not to mention having long established integrated facilities and economies of scale. You'd have to enter the global marketplace with a car company built from scratch, that would need billions if not even maybe hundreds of billions dumped into R&D, design & development, which takes time. You would need manufacturing facilities that would be huge, that would also probably cost tens if not hundreds of billions to develop. Where is your steel going to come from? How are you going to stamp it? Where's all the parts coming from if you don't want to work with the US, and then how are you going to get them on a timely basis if they are coming by ship? Not to mention the zillion other questions one would need to figure out. It would take ~a decade to get this all sorted out. And godless sums of money. All to then compete in a global marketplace with international companies that have centuries of experience.

Magna would be the only developed enough option where this could even be feasible, but even they've sort of poked around looking at developing a product in the past, and the absence of said product in the marketplace kind of tells you everything you need to know about the viability of it.