You could warm Mars up, over time, with greenhouse gases.
The rumours of the demise of the U.S. manufacturing industry are greatly exaggerated.
The U.S. automotive industry has been selling cars the same way for over 100 years, and there are many laws in place to govern exactly how that is to be accomplished.
I tend to approach things from a physics framework. And physics teaches you to reason from first principles rather than by analogy.
People work better when they know what the goal is and why. It is important that people look forward to coming to work in the morning and enjoy working.
SpaceX is only 12 years old now. Between now and 2040, the company's lifespan will have tripled. If we have linear improvement in technology, as opposed to logarithmic, then we should have a significant base on Mars, perhaps with thousands or tens of thousands of people.