Mass production reduces costs by standardizing things. But still, car companies offer a wide range of options if you're willing to wait for your order. If Ford doesn't provide what you want, there's GM, Toyota, Hyundai, etc. There's no shortage of variety.
There's also a small cottage industry of people who will make fully custom cars for you. They're pretty expensive, though, as they don't benefit from economies of scale.
There's also a small cottage industry of people who will make fully custom cars for you. They're pretty expensive, though, as they don't benefit from economies of scale.