If the world only had American automobiles, the automotive industry would be significantly different. The cars we drive would look and feel different, and people from all over the world would be affected. American cars are known for their power, size, and fuel economy, so if this were the only option for cars, our daily commutes would look different. We would also have to consider the environmental impact of having only American cars on the road. The world would be a much different place if we only had American automobiles. We'd have to adjust to this new reality and find a way to make the best of it.