There is market opportunity, China has found it, but the US won't allow them to be imported because it undercuts everyone else so thoroughly. The US automotive market is extremely far from being a free and open market. You can't just build a car to a set of standards and automatically be allowed to sell them, there are substantial legal and political barriers that cost tons of money to overcome, which doesn't make financial sense to anyone with that amount of money to just sell low margin vehicles.