Restoring a vintage car is a labor of love. While admittedly there are some that do this as a business, all of them, those that restore and collect vintage cars, are driven by their passion, they are fueled by their desire for vintage cars and watching them return to their full glory is what makes them happy.
Ownership of a vintage car sets an image of glamour, prestige and a status symbol that shows you can afford its high maintenance, think Jay Leno. Aside from having the money to pursue such an endeavor, you should also have the passion for it. You need to be very patient when restoring a vintage car.