While this is true in theory, from my experience of running businesses and from talking to accountants and bank employees, this doesn't work for most people. A corporation or llc can shield you, but unless the company has a proven revenue stream or assets, no bank or landlord will take on risk without asking you to assume personal liability as well.

Kind of like needing a cosigner when you get that first car.

your exactly right. only way to get money for a business like that is credit cards, second mortgage etc.