Sure, we've made cars in the past. It wouldn't be a great idea, since others have certainly mastered the craft now. If we do it, it's because Trump is being a **** on trade – but it's better to just import from Europe, Japan and Korea if so, because starting a whole new brand for scratch is expensive and it takes 10-15 years to work all the kinks out. Korean cars in the 80s were cheap crap. Now, they're actually pretty solid. Same with Japanese cars in the 60s.
No. Canada is a country, not a business owner.
Lots of vehicle manufacturers have started up in Canada, and all of them have since closed. They were either bought up by foreign companies, or just went out of business on their own.