Do you have lots of money? If not, you’ll need to find investors who’ll be willing to put their nose into your company and persuade them that your product will sell and turn a profit for them.
And unless you’re willing to do all the research and work that goes into designing and building a car yourself (there’s plenty of resources out there; nobody is stopping you), you’ll need to hire people to do that, and they will want to be paid lots of money.
Take some business and engineering classes while you’re still in school. Borrow some books from the library. I hope you like math because I suspect you’ll need to know calculus to be successful in the engineering and economics sides of things.